Deploying IBM Flex System into a Cisco Network

International Technical Support Organization
Deploying IBM Flex System into a Cisco Network
February 2013
REDP-4901-00

© Copyright International Business Machines Corporation 2013. All rights reserved.
Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule
Contract with IBM Corp.
First Edition (February 2013)
This edition applies to the following switches and firmware levels:
򐂰 IBM Flex System EN2092 1Gb Ethernet Scalable Switch: Version 7.2.2.2
򐂰 IBM RackSwitch G8264: Version 7.2.2.0
򐂰 Cisco Nexus 5000: Version 5.1(3)N2(1)
򐂰 Cisco Catalyst 6500: Version 12.2.33-SXH8a
Note: Before using this information and the product it supports, read the information in “Notices” on
page vii.

© Copyright IBM Corp. 2013. All rights reserved. iii
Contents
Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
The team who wrote this paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Now you can become a published author, too! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Comments welcome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv
Stay connected to IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv
Chapter 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 IBM PureSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Switch configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 How to use this paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Chapter 2. Layer 2 Network protocols and technologies . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Basic frame forwarding concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Virtual local area network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Spanning tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.1 Spanning Tree Protocol: IEEE 802.1D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2 Rapid Spanning Tree Protocol: IEEE 802.1w . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3.3 Multi-instance Spanning Tree Protocol: IEEE 802.1s . . . . . . . . . . . . . . . . . . . . . . 10
2.3.4 Per VLAN Rapid Spanning Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4 Link aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4.1 Link Aggregation Control Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4.2 Virtual Link Aggregation Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4.3 Cisco Virtual Port Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4.4 Link Layer Discovery Protocol: 802.1AB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Chapter 3. IBM RackSwitch G8264 connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2 Use Case 1: PVRST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2.1 Verifying the topology by using lldp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2.2 Verifying trunks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.3 Verifying PVRST spanning tree configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2.4 Show running-config of all switches in Use Case 1 . . . . . . . . . . . . . . . . . . . . . . . 25
3.3 Use Case 2: Link aggregation and PVRST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.1 Verifying the topology that is used by using lldp . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.3.3 Verifying link aggregation by using lacp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.3.4 Verifying PVRST spanning tree configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.4 Use Case 3: Link aggregation and MST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.4.1 Verifying the topology that was used by using lldp . . . . . . . . . . . . . . . . . . . . . . . . 49
3.4.3 Verifying link aggregation by using lacp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.4.4 Verifying MST spanning tree configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

iv Deploying IBM Flex System into a Cisco Network
3.5 Use Case 4: Link aggregation, MSTP and VLAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.5.2 Verify interface status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.5.4 Verify spanning tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.5.5 Verify virtual link aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.6 Use Case 5: Link aggregation and VLAG without STP. . . . . . . . . . . . . . . . . . . . . . . . . 78
3.6.2 Verify interface status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
3.6.4 Verify virtual link aggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Chapter 4. Cisco Nexus 5000 connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.2 Use Case 1: PVRST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.2.1 Verifying the topology that is used by using lldp . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.2.3 Show running-config of all switches in Use Case 1 . . . . . . . . . . . . . . . . . . . . . . 105
4.3 Use Case 2: PVRST with LACP Channeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.3.1 Verifying the topology used by using lldp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.3.2 Verifying trunks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
4.3.3 Verifying PVRST spanning tree configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . 115
4.3.4 Bridge priority field in the show spanning tree output . . . . . . . . . . . . . . . . . . . . . 118
4.4 Use Case 3: MST with LACP Channeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
4.4.1 Verifying the topology used by using lldp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
4.4.2 Verifying trunks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
4.4.3 Verifying MST spanning tree configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
4.5 Use Case 4: MST with LACP Channeling and vPC . . . . . . . . . . . . . . . . . . . . . . . . . . 141
4.5.1 Configuring vPC on STR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
4.5.2 Configuring MST on the STR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
4.5.3 Configuring vPC on VIE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
4.5.4 Configuring MST on VIE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
4.5.5 Reviewing the Flex System switch configuration . . . . . . . . . . . . . . . . . . . . . . . . 145
4.5.6 Configuring MST on the Flex System switch . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
4.5.7 Logical view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
4.5.8 Verifying the configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
4.5.9 Verifying the vPC configuration on VIE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
4.6 Use Case 5: LACP Channeling and vPC without spanning tree. . . . . . . . . . . . . . . . . 162
4.6.1 Configuring vPC on STR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
4.6.2 Configuring vPC on VIE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
4.6.3 Disabling STP on the Flex System switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Chapter 5. Cisco Catalyst 6500 switch connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . 171
5.1 Use Case 1: LACP channeling and vPC without spanning tree . . . . . . . . . . . . . . . . . 172
5.1.1 Catalyst 6500 switch configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
5.1.2 Flex System switch configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Appendix A. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Basic troubleshooting for connectivity problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Contents v
Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Layer 2 troubleshooting commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Baseline documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Additional useful information for baseline documentation. . . . . . . . . . . . . . . . . . . . . . . 183
Firmware update of IBM Flex System network switches . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Update the switch by using the web-based GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Using SSHv2 or Telnet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Abbreviations and acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Other publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Online resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Help from IBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

vi Deploying IBM Flex System into a Cisco Network

© Copyright IBM Corp. 2013. All rights reserved. vii
Notices
This information was developed for products and services offered in the U.S.A.
IBM may not offer the products, services, or features discussed in this document in other countries. Consult
your local IBM representative for information on the products and services currently available in your area. Any
reference to an IBM product, program, or service is not intended to state or imply that only that IBM product,
program, or service may be used. Any functionally equivalent product, program, or service that does not
infringe any IBM intellectual property right may be used instead. However, it is the user's responsibility to
evaluate and verify the operation of any non-IBM product, program, or service.
IBM may have patents or pending patent applications covering subject matter described in this document. The
furnishing of this document does not grant you any license to these patents. You can send license inquiries, in
writing, to:
IBM Director of Licensing, IBM Corporation, North Castle Drive, Armonk, NY 10504-1785 U.S.A.
The following paragraph does not apply to the United Kingdom or any other country where such
provisions are inconsistent with local law: INTERNATIONAL BUSINESS MACHINES CORPORATION
PROVIDES THIS PUBLICATION “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR
IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-INFRINGEMENT,
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow disclaimer of
express or implied warranties in certain transactions, therefore, this statement may not apply to you.
This information could include technical inaccuracies or typographical errors. Changes are periodically made
to the information herein; these changes will be incorporated in new editions of the publication. IBM may make
improvements and/or changes in the product(s) and/or the program(s) described in this publication at any time
without notice.
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manner serve as an endorsement of those websites. The materials at those websites are not part of the
materials for this IBM product and use of those websites is at your own risk.
IBM may use or distribute any of the information you supply in any way it believes appropriate without incurring
any obligation to you.
Any performance data contained herein was determined in a controlled environment. Therefore, the results
obtained in other operating environments may vary significantly. Some measurements may have been made
on development-level systems and there is no guarantee that these measurements will be the same on
generally available systems. Furthermore, some measurements may have been estimated through
extrapolation. Actual results may vary. Users of this document should verify the applicable data for their
specific environment.
Information concerning non-IBM products was obtained from the suppliers of those products, their published
announcements or other publicly available sources. IBM has not tested those products and cannot confirm the
accuracy of performance, compatibility or any other claims related to non-IBM products. Questions on the
capabilities of non-IBM products should be addressed to the suppliers of those products.
This information contains examples of data and reports used in daily business operations. To illustrate them
as completely as possible, the examples include the names of individuals, companies, brands, and products.
All of these names are fictitious and any similarity to the names and addresses used by an actual business
enterprise is entirely coincidental.
COPYRIGHT LICENSE:
This information contains sample application programs in source language, which illustrate programming
techniques on various operating platforms. You may copy, modify, and distribute these sample programs in
any form without payment to IBM, for the purposes of developing, using, marketing or distributing application
programs conforming to the application programming interface for the operating platform for which the sample
programs are written. These examples have not been thoroughly tested under all conditions. IBM, therefore,
cannot guarantee or imply reliability, serviceability, or function of these programs.

viii Deploying IBM Flex System into a Cisco Network
Trademarks
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Corporation in the United States, other countries, or both. These and other IBM trademarked terms are
marked on their first occurrence in this information with the appropriate symbol (® or ™), indicating US
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The following terms are trademarks of the International Business Machines Corporation in the United States,
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IBM Flex System™
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PureFlex™
PureSystems™
RackSwitch™
Redbooks®
Redpaper™
Redbooks (logo) ®
System x®
zEnterprise®
The following terms are trademarks of other companies:
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countries, or both.
Other company, product, or service names may be trademarks or service marks of others.

© Copyright IBM Corp. 2013. All rights reserved. ix
Foreword
This IBM® Redpaper™ publication was initiated and authored by members of the Technical
Expert Council, Central Region (TEC CR) workgroup “Workload optimized networks” that was
founded November 2011. When IBM moved back into the networking market with the
acquisition of BNT, this move positioned IBM to capture a significant share of an emerging
market for converged fabrics.
The initial idea of the workgroup was that Ethernet will become pervasive for all aspects of
networking and storage in the next couple of years, which requires users to rethink how
connectivity aspects become an integrated part of any computing solution. The workgroup
established an expert community to bring development expertise, networking background,
and customer and market insights together. Business sponsor of the TEC workgroup is Erich
Baier, IBM Vice President, who is responsible for Modular Systems and Networking
Development.
The TEC CR is the local affiliate for Germany, Switzerland, and Austria of the IBM Academy
of Technology (AoT). The mission of the TEC CR is to strengthen the technical leadership in
the local markets through promoting communication among experts and by consulting the
executive management of IBM. It identifies and pursues technical opportunities that are
relevant to the business of IBM, and aims to advance the technology base of IBM and its
application in market-leading products, solutions, and services.
A major finding from the collaboration in the workgroup was that with the announcement of
IBM PureSystems, many clients will have to integrate IBM Flex System into a typical Cisco
dominated customer network. However, the documentation that is needed to complete this
integration was not readily available. In close collaboration with the development labs, the
group took initiative to close the gap and wrote this paper.
This paper is a good example of a collaborative effort of technical experts and leaders from
different organizations that results in a holistic view of the relevant steps that are needed to
make a solution successful in the market. As a chairman of the TEC CR, I would like to thank
the authors of the paper for this initiative.
Thomas Harrer
Chairman, Technical Expert Council, Central Region (TEC CR)
Member IBM Academy of Technology

x Deploying IBM Flex System into a Cisco Network

© Copyright IBM Corp. 2013. All rights reserved. xi
Preface
This IBM® Redpaper™ publication provides information about how to integrate an IBM Flex
System into an existing customer network. It focuses on interoperability and seamless
integration from the network perspective.
The paper describes the complete configuration of the most common scenarios. It guides you
through several setups, and shows in detail how to configure the network switches and verify
the functionality and proper operation.
This paper can help you to easily configure and monitor your Layer 2 setup. Typical,
well-established Layer 2 Network setups use combinations of Spanning Tree Protocol,
VLANs, and link aggregation.
The scenarios that are described in this paper include the use of the following switching
products:
򐂰 Cisco Nexus 5000 (including vPC)
򐂰 Cisco Catalyst 6500
򐂰 IBM RackSwitch (including VLAG)
򐂰 IBM Flex System Ethernet Scalable Switch (including VLAG)
We describe the use of these switches with each of the following Spanning Tree Protocol
(STP) configurations:
򐂰 RSTP (Rapid STP)
򐂰 MSTP (Multiple STP)
򐂰 PVRST (Per VLAN Rapid STP)
򐂰 STP disabled
The paper is for network administrators who are familiar with Cisco network products. It uses
the industry standard command-line interface (isCLI) as the management interface. It is
assumed that the reader is familiar with Cisco products and the use of isCLI.
The team who wrote this paper
This paper was produced by a team of specialists from around the world.
Christoph Raisch is a Senior Technical Staff Member at IBM Germany Research &
Development, Boeblingen. He has 15 years of experience in defining and implementing
firmware architectures in the areas of Fibre Channel, InfiniBand, PCI Express, Ethernet, and
FCoE for different IBM platforms. He received a Dipl.-Ing. degree in Electrical Engineering
from the University of Stuttgart. He works on future technologies for IBM networking switches.
Bernd Albrecht is an IT Specialist in IBM Germany specializing in IBM PureSystems and
Storage. He has 21 years of experience in technical sales, starting with MVS, then eight years
with AIX. For the past 12 years, he has worked in the storage and SAN product areas. He
holds a degree as Graduate Engineer in Computer Science from the University of Dresden.
He has co-authored eight IBM Redbooks publications. His current focus is working in the
open storage area, storage virtualization, SAN, and PureSystems.

xii Deploying IBM Flex System into a Cisco Network
Peter Demharter is an IBM certified Senior Architect IT Infrastructure and Cisco Certified
Internetwork Expert in Germany. He has over 20 years of experience in the data center and
networking area and has worked for large companies, such as Daimler-Benz and Vodafone.
He holds a degree in Administration and Information Science from the University of
Constance. He has worked for IBM GTS for 10 years and has served as lead Architect in IBM
projects such as ABB worldwide WAN migration from Equant to AT&T, and Deutschland
Online Infrastructure, one of the first corporate IPv4/IPv6 dual stack wide area networks in
Germany. He works for the IBM Research and Development Global Design Center in
Boeblingen and focuses on IPv6, DC Networking, and Cloud Computing.
Stephan Fleck is a System Network Architect for IBM Systems & Technology Group, Europe.
He has 19 years experience in the IT industry. His areas of expertise include network
architecture assessments and network designs for data centers, and implementation
proposals for network virtualization and network convergence solutions. Stephan also
conducts training sessions for technical and sales personnel and he speaks regularly at
technical conferences. He has worked as Network Security Lead Architect for the IBM Global
Account and as support specialist for the European Network Support Back Office. Stephan is
a Cisco Certified Internetwork Expert and holds a degree in electrical engineering from the
Technical University Darmstadt, Germany.
Joachim Gross is an IT Architect and expert for network infrastructure in Germany. He has
20 years of experience in the networking area field as a Cisco Certified Internetwork Expert
since 1995. He holds a degree in Information Technology from the FH in Esslingen, Germany.
Working for IBM GTS for over 10 years, he has participated in worldwide networking and
Voice over IP projects. His areas of expertise include data center networking and Voice over
IP.
Ruediger Rissmann holds a Diploma Degree in Physics from the University of Heidelberg,
Germany, and joined the IBM Zurich Research Laboratory in 1999. In his position as a
network specialist, he has been involved in several pilot projects that explore new and
emerging network technologies and has filed a number of patents. He leads the worldwide
IPv6 deployment within the IBM Research Division. In March 2011, Ruediger became a
research staff member and senior architect in the Services Innovation Lab. He holds the
following certifications: IBM Certified IT Architect, Open Group Master Certified IT Architect,
CCNP, CISSP, and GCFA.
Werner Sponer is a Senior IT Architect and expert for network infrastructure and security. He
is responsible for network infrastructure and System Networking products in the System and
Technology Group of IBM. He spent most of his 20-plus years at IBM growing the Global
Services business through technical advancements. His assignments ranged from
infrastructure to consulting and audit services, including projects and managed services. He
brings over 18 years of IT experience in networking, data center, network architecture, local
and wide area network, operation and support of IT infrastructure, in different customer
industries and technologies. He evolves his leadership skills and customer orientation in
different project scenarios in several countries, from consulting and planning, architecture,
and design to operation and support. He is an engineer for electronic and biomedical
technologies and IBM and Open Group Certified IT Architect.
Arwed Tschoeke is a Client Technical Architect in Hamburg, Germany. His focus areas are
zEnterprise, virtualization solutions across IBM platforms, and Linux. He holds a degree in
Physics from the University of Kaiserslautern, Germany.

Preface xiii
Pietro Volante is a Certified IT Specialist for Networking Services. He has 20 years of
experience in designing and implementing networks in many large client situations. He is
certified as a Cisco Network and Design Professional (CCNP/CCDP) and has experience in
designing data center networks and network performance analysis. In 2010, he worked on an
assignment at STG to provide technical network support for the new BladeCenter network
switches across north east Europe. He is responsible for projects in data center network
integration and end-to-end network application performance analysis at key accounts.
Thanks to the following people for their contributions to this project:
򐂰 Erich Amrehn
򐂰 Bernhard Dierberger
򐂰 Oliver Raff
򐂰 Thomas Schwaller
򐂰 David Watts
Portions of this paper were based on the IBM Redbooks® publication, Implementation of IBM
j-type Ethernet Switches and Routers, SG24-7882. Thanks to the authors of that paper.
Now you can become a published author, too!
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area of expertise, while honing your experience using leading-edge technologies. Your efforts
will help to increase product acceptance and customer satisfaction, as you expand your
network of technical contacts and relationships. Residencies run from two to six weeks in
length, and you can participate either in person or as a remote resident working from your
home base.
Find out more about the residency program, browse the residency index, and apply online at
this website:
http://www.ibm.com/redbooks/residencies.html

xiv Deploying IBM Flex System into a Cisco Network
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© Copyright IBM Corp. 2013. All rights reserved. 1
Chapter 1. Introduction
With the release of PureSystems™, IBM launched a second hybrid computing platform to the
market. zEnterprise® with zBX is focused on mainframe affine applications with a simplified
workload-oriented management approach. PureSystems offers various implementation
possibilities that are focused on a cloud-oriented customer strategy.
To deliver value, PureSystems consists of the following building blocks:
򐂰 Management
The Flex System Manager simplifies and automates all management tasks. It also
manages all physical and virtual resources within the solution. Hence, it offers a full
integration and infrastructure-as-a-service-like management of PureSystems.
򐂰 Compute Nodes
To select the system that fits best to your requirements, it is possible to mix Power
Systems and System x® compute nodes within the PureSystems Chassis.
򐂰 Storage
The Storwize V7000 storage controller delivers automatic EasyTierung of storage
controller internal storage and the possibility to take advantage of external storage at the
same time. With its built-in storage virtualization, simple and comprehensive management
is possible via the integrated management of PureSystems.
򐂰 Networking
PureSystems provide a choice of adapters and switches. All components are
standard-based and integrated into the management of PureSystems. This variety
provides a combination of features that fits into the existing infrastructure. The modular
concept offers the possibility to adapt to future requirements.
To use the capabilities of PureSystems, in most cases a connection to an existing network is
required. However, modern datacenters rely on a complex network infrastructure. The
introduction of active networking components within an existing infrastructure can affect all
components and poses a risk. Therefore, many customers are reluctant to introduce such
solutions.
1

2 Deploying IBM Flex System into a Cisco Network
1.1 Networking
Many customers are currently migrating their networking infrastructure from 1 Gb Ethernet to
10 Gb Ethernet. This transformation exceeds the simple change of technology and
requirements increased significantly. The complexity of modern application infrastructures
requires networks of low latency at high bandwidth. Additionally, growing security awareness
affects the design of a network and increases the complexity (for example, router, firewalls,
filters). Because of virtualization and the adoption of cloud concepts, the physical network
infrastructure merges with a logical and virtual networking environment that is represented by
software components that are running on server systems.
As a result, there is no average network or general blueprint. Each network is unique because
it depends on the customer’s demands. Often, customers choose individual components from
vendors that meet their requirements. From this decision, the following challenges arise:
򐂰 The administration of such mixed infrastructures is rather complex and often requires
more management concepts.
򐂰 Testing and maintaining interoperability is elaborate and time-consuming.
To overcome these challenges, customers’ adopt a single-vendor strategy. This strategy
offers a simplification in the daily routine but can restrict the adoption of new solutions if they
are not supported by the infrastructure vendor.
To support their customers, the industry defines standards. Based on those standards,
interoperability between vendors can be achieved. This interoperability offers the opportunity
to adapt the latest technology and limit the risk to the administration.
However, new standards are adopted by vendors at different times and not all choose to
follow standards rigorously. Instead, they might provide their own extensions. One example of
this issue is the integration of virtualized environments into the networking infrastructure. The
networking branch of IBM is investing with other vendors a significant amount of energy to
define global standards that support the mobility of virtual systems and infrastructures, such
as vswitches. This effort delivers the availability of functions that allow a guest relocation
between different systems that are independent of the hypervisor or the networking
components within the physical infrastructure.
1.2 IBM PureSystems
The PureSystems platform is a new approach to deliver scalable hybrid systems for the
adoption of modern cloud concepts. Its design delivers value to the customer by fulfilling the
following requirements:
򐂰 Simplification to ease the implementation of complex solutions and operation
򐂰 Built in expertise to ease deployment and capacity planning
򐂰 Integration within the existing architectures and infrastructure
These advantages are achieved by a new hardware and system management concept. To
reflect this concept, the systems are labeled Expert Integrated Systems. The following
PureSystems offerings are available:
򐂰 PureFlex™ System: An infrastructure system that monitors capacity and performance to
optimize the infrastructure (Infrastructure-as-a-Service within the cloud terminology).

Chapter 1. Introduction 3
򐂰 PureApplication System: A platform system that is based on a flexible infrastructure that
provides the means of deploying and maintaining an application infrastructure that is
based on patterns (Platform-as-a-Service within the cloud terminology).
򐂰 PureData System: Based on the PureApplication concept, this solution is focused on
delivering data services by providing a fully managed, flexible, and highly available
database platform that meets all demands.
The foundation of these Expert Integrated Systems is the PureSystems hardware, which
consists out-of-server hardware (Power and x86), storage, and network, such as storage area
network (SAN) and local area network (LAN). The design principle inherits the BladeCenter
philosophy of IBM to open standards, manageability, serviceability, and an existing roadmap
for investment protection.
To provide full flexibility, many active infrastructure components are available. The LAN
components are derived from the networking technology of IBM, which ensures that an
in-depth integration into virtual environments is possible. Because of the broad support of
networking standards, this ability applies to physical networks as well.
For more information about IBM PureSystems, see Overview of IBM PureSystems,
TIPS0892, which is available at this website:
http://www.redbooks.ibm.com/abstracts/tips0892.html
1.3 Switch configuration
IBM System Networking switches can be configured through multiple configuration interfaces.
For this paper, the iSCLI method was chosen. Its syntax should be familiar to network
administrators with experience in switches from other vendors.
Important: This Redpaper uses the show running-config configuration dumps to
demonstrate how the switches were configured. These dumps include all of the command
sequences that are required to configure the switch manually.
For more information, see the Configuration Dump section of the Configuration Commands
chapter in ISCLI–Industry Standard CLI Command Reference for the IBM Flex System
Fabric EN4093 10Gb Scalable Switch, which is available at this website:
http://publib.boulder.ibm.com/infocenter/flexsys/information/index.jsp?topic=%2
Fcom.ibm.acc.networkdevices.doc%2FIo_module_compass.html

1.4 How to use this paper
We recommend that you read Chapter 2, “Layer 2 Network protocols and technologies” on
page 5 first to clarify the use of technical terms. Then, based on the networking hardware you
have, select the following appropriate chapter to read next:
򐂰 Chapter 3, “IBM RackSwitch G8264 connectivity” on page 15
򐂰 Chapter 4, “Cisco Nexus 5000 connectivity” on page 95
򐂰 Chapter 5, “Cisco Catalyst 6500 switch connectivity” on page 171
Within each of these chapters, you can review subsections that relate to the choice of
Spanning Tree Protocol that you use.
Finally, Appendix A, “Troubleshooting” on page 177, describes different aspects of problem
analysis and identifies information that is required for efficient troubleshooting.

Chapter 2. Layer 2 Network protocols and
technologies
Open systems interconnection (OSI) Layer 2 (or, the DataLink Layer) provides the functional
means for data transfer between adjacent nodes in the network. Layer 2 also provides the
lowest level of addressability in an Ethernet network that uses MAC addresses.
The MAC address contains 48 bits that are split into two, 24-bit sections. The first 24-bit
section is assigned by IEEE to reflect the organizationally unique identifier (OUI)). Each
Ethernet hardware manufacturer has one or more of these OUIs. The second 24-bit section is
created by the manufacturer. The combination of these two 24-bit sections should guarantee
that the MAC address is always unique in a LAN.
This chapter includes the following topics:
򐂰 Basic frame forwarding concepts
򐂰 Virtual local area network
򐂰 Spanning tree
򐂰 Link aggregation
2

2.1 Basic frame forwarding concepts
Each frame contains a source and a destination MAC address. A network bridge or switch,
also called Layer 2 device, is responsible to transport the Ethernet frame that is based on the
destination MAC address.
Figure 2-1 shows the simplified principle of frame forwarding.
Figure 2-1 Simplified principle of frame forwarding
The forwarding of an incoming frame (on port 1 in this case) is divided into the following
phases:
򐂰 Learning
Ethernet Frame arrives on port1. Switch learns source MAC Address (SA) and stores this
fact it in its MAC Address Table.
򐂰 Lookup
Based on the destination MAC address (DA), the switch looks up the correct routing in its
MAC address table and selects the outgoing port (port 6).
򐂰 Forwarding
The switch forwards the Ethernet frame to the destination MAC address via port 6.
If the switch does not know the destination address, it forwards the packet on all ports except
the port from which it was received.
During this forwarding process, the frame header persists unmodified.
Switch (Layer-2)
1 2 3 4 5 6
MAC Address Table
MAC Address Port
ABAB.1122.4455 1
ABAB.1122.4466 2
...
ABCC.4231.3303 5
ABCC.2331.4213 6
DA
SA
Data
CRC
SA: ABAB.1122.4455
DA: ABCC.2331.4213
SA: ABAB.1122.4455
DA: ABCC.2331.4213
1. Learning:
Frame arrives on port1.
Switch learns source
MAC Address (SA) and
stores it in its MAC
Address Table.
2. Lookup:
Based on the destination
MAC address (DA), the
switch selects the
outgoing port.
2
3. Forwarding:
Switch forwards the
incoming frame to the
destination.
3
1
1

Chapter 2. Layer 2 Network protocols and technologies 7
2.2 Virtual local area network
A virtual local area network (VLAN) is a networking concept in which a network is logically
divided into smaller virtual LANs. The Layer 2 traffic in one VLAN is logically isolated from
other VLANs, as shown in Figure 2-2.
Figure 2-2 Isolation at Layer 2
The simplest way to keep the isolated VLANs separately on an inter-switch link is to use one
physical link for each VLAN, as shown in Figure 2-3.
However, this method does not scale well because it uses many ports in networks with
multiple VLANs and multiple switches. Also, this method does not use link capacity efficiently
when traffic in the LANs is not uniform.
Figure 2-3 Inter-switch link: one link for each VLAN
The second method is VLAN tagging over a single link in which each frame in tagged with its
VLAN ID (see Figure 2-4 on page 8). This method is highly scalable because only a single
link is required to provide connectivity to many VLANs. This configuration provides for better
utilization of the link capacity when VLAN traffic is not uniform.
The protocol for VLAN tagging of frames in a LAN environment is defined by the IEEE 802.1
P/Q standard.
VLAN20
VLAN20
VLAN30
VLAN10
VLAN10
VLAN30
Inter Switch Link
using VLAN Tagging
VLAN30
VLAN20
VLAN10

Figure 2-4 Inter-switch link that uses VLAN tagging
2.3 Spanning tree
Because of the history of LANs and Ethernet, there are some shortcomings in the protocol. In
particular, Ethernet was not designed to use frame forwarding. Therefore, the frame format
does not include a hop count field, or time-to-live (TTL), which would allow for a looping
packet to be detected and discarded. Packets that are sent in a loop between multiple
switches are forwarded without reaching their destination, which can cause significant load.
The simplest approach to prevent looping packets is to create a network topology in which
frames with a certain target can take only one path on each individual switch element. For
Ethernet, the tree topology was chosen, which is the simplest topology that guarantees this
requirement. Bridges and switches were enhanced to support a topology configuration
protocol called Spanning Tree Protocol (STP).
STP provides Layer 2 loop prevention by deactivating redundant routes between network
elements. This configuration has been further enhanced and is now used in the following
forms:
򐂰 STP
򐂰 Rapid STP (RSTP)
򐂰 Multiple STP (MSTP)
򐂰 Per VLAN STP or Per VLAN Rapid STP (PVRST)
STP was the initial implementation of Spanning-Tree Protocol, which was invented 1985 and
published 1990 in the IEEE as 802.1D.
Rapid Spanning Tree (RSTP) became standard in IEEE in 2001 as 802.1w. It provides faster
convergence times than STP.
Multiple Spanning Tree (MSTP) was first defined in IEEE as 802.1s and later merged into
802.1Q-2005 as an extension to RSTP. It uses more than one Spanning Tree process to
distribute the VLANs into different STP topologies.
Cisco provides a proprietary version of VLAN-based STP. For each VLAN, it uses a separate
Spanning Tree. Even if it is not an IEEE standard, many network vendors allow compatible
setup to interoperate with Cisco’s STP.
VLAN20
VLAN20
VLAN20
VLAN20
Tagged Link

2.3.1 Spanning Tree Protocol: IEEE 802.1D
STP uses Bridge Protocol Data Unit (BPDU) packets to exchange information with other
switches. BPDUs send out hello packets at regular intervals to exchange information across
bridges and detect loops in a network topology.
The following types of BPDUs are available:
򐂰 Configuration BPDU
These BPDUs contain configuration information about the transmitting switch and its
ports, including switch and port MAC addresses, switch priority, port priority, and port cost.
򐂰 Topology Change Notification (TCN) BPDU
When a bridge must signal a topology change, it starts to send TCNs on its root port. The
designated bridge receives the TCN, acknowledges it, and generates another TCN for its
own root port. The process continues until the TCN reaches the root bridge.
򐂰 Topology Change Notification Acknowledgement (TCA) BPDU
These frames are sent by the root bridge to acknowledge the receipt of a TCN BPDU.
STP uses the information that is provided by the BPDUs to elect a root bridge, identify root
ports for each switch, identify designated ports for each physical LAN segment, and prune
specific redundant links to create a loop-free tree topology. All leaf devices calculate the best
path to the root device and place their ports in blocking or forwarding states that are based on
the best path to the root. The resulting tree topology provides a single active Layer 2 data
path between any two end stations.
Figure 2-5 shows a switch topology with five interconnected switches. To avoid
Layer 2-looped frames, Spanning Tree blocks all ports that include an indirect, redundant path
to the root bridge. As shown in Figure 2-5, the resulting logical switch topology is based on
the STP calculation.
Figure 2-5 Switch topology with five interconnected switches
Root Bridge
Desg.Port Desg.Port
Root.Port
Blkd.Port
Root Bridge
Desg.Port Desg.Port
Desg.Port
Desg.Port
Root.Port
Blkd.Port
Root.Port Root.Port Root.Port
Root.Port Root.Port
Desg.Port
Desg.Port
Root.Port
Desg.Port
X
X
All redundant ports to root bridges blocked Resulting loop free topology

The root bridge election is an important point in a network design. To avoid suboptimal
Layer 2 paths, it is always necessary to manually adjust the bridge priority on each switch in a
Layer 2 network.
2.3.2 Rapid Spanning Tree Protocol: IEEE 802.1w
Rapid Spanning Tree Protocol (RSTP) provides better reconvergence time than the original
STP. RSTP identifies certain links as point-to-point. When a point-to-point link fails, the
alternative link can make the transition to the forwarding state.
An RSTP domain includes the following components:
򐂰 Root port: The “best path” to the root device.
򐂰 Designated port: Indicates that the switch is the designated bridge for the other switch that
connects to this port.
򐂰 Alternative port: Provides an alternative root port.
򐂰 Backup port: Provides a designated alternative port. This configuration is used if there is
more than one link that is connected to the same switch without link aggregation.
RSTP uses the following port states by using the show spanning tree command:
򐂰 Discarding: Like the blocking-state in STP, this port does not forward traffic to avoid loops.
򐂰 Learning: The port builds its MAC address table but does not forward traffic.
򐂰 Forwarding: The port forwards traffic.
The RSTP reconvergence time often is less than 1 second. The standard STP (802.1d)
requires 30 seconds or more.
RSTP was originally defined in the IEEE 802.1w draft specification and later incorporated into
the IEEE 802.1D-2004 specification.
2.3.3 Multi-instance Spanning Tree Protocol: IEEE 802.1s
Although RSTP provides faster convergence time than STP, it does not solve a problem
inherent in STP. All VLANs within a LAN must share the same spanning tree while many links
in the network could be unused. To solve this problem, the existing STP concepts are no
longer applied to physical ports. The concepts are applied to the connectivity of multiple
individual groups of VLANs, called spanning tree regions, instead.
In a Multi-instance Spanning Tree Protocol (MSTP) region, a group of bridges can be
modeled as a single bridge. An MSTP region contains multiple spanning tree instances
(MSTIs). MSTIs provide different paths for different VLANs. This functionality facilitates better
load sharing across redundant links.
An MSTP region can support up to 64 MSTIs, and each instance can support 1 - 4094
VLANs.
MSTP was originally defined in the IEEE 802.1s draft specification and later incorporated into
the IEEE 802.1Q-2003 specification.

2.3.4 Per VLAN Rapid Spanning Tree
Per VLAN Rapid Spanning Tree (PVRST) is a nonstandard spanning tree extension that is
based on RSTP that was introduced by Cisco Systems. In PVRST mode, each VLAN is
assigned to its own spanning-tree group. A maximum of 127 spanning tree groups are
allowed in IBM System Networking switches.
PVRST use 802.1Q tagged frames to differentiate STP BPDUs for each VLAN. The IIBM
System Networking implementation of PVRST is fully compatible with Cisco RSTP/PVRST+
protocol.
2.4 Link aggregation
A link aggregation group (LAG) combines physical links to operate as a single, larger logical
link. The member links no longer function as independent physical connections, but as
members of the larger logical link, as shown in Figure 2-6.
Figure 2-6 Link aggregation
Link aggregation provides greater bandwidth between the devices at each end of the
aggregated link. Another advantage of link aggregation is increased availability because the
aggregated link is composed of multiple member links. If one member link fails, the
aggregated link continues to carry traffic over the remaining member links.
Each of the devices that are interconnected by the aggregated link uses a hashing algorithm
to determine on which of the member links frames will be transmitted. The hashing algorithm
might use varying information in the frame to decide. This algorithm might include a source
MAC, destination MAC, source IP, destination IP, and more. It might also include a
combination of these values.
Link aggregation can be defined as static or by using a dynamic negotiation protocol, such as
Link Aggregation Control Protocol (LACP). Aggregated links often are referred to as
Ether-Channels or Trunk-Links.
Aggregated links appear to the STP as single logical links. Therefore, STP does not enable or
disable individual physical links of an aggregated link.
Aggregate
Links

2.4.1 Link Aggregation Control Protocol
LACP (also known as 802.3ad and, more recently, 802.1AX-2008) is a vendor-independent
standard for dynamically building aggregated links between switches. On an LACP-defined
link, the switches are sending LACP Data Units (LACPDU) to share information about the
current state of the aggregated link. Compared to static LAG, LACP provides better failure
detection and, therefore, a higher redundancy.
2.4.2 Virtual Link Aggregation Groups
Virtual Link Aggregation Groups (VLAGs) is an extension to link aggregation to allow more
redundancy. For a standard LAG (static or dynamic), all ports that build an aggregated link
must be on the same switch. VLAG allows two switches to pair as a single virtual entity to
build an aggregated link that is distributed to both switches. From the perspective of the target
device, the ports that are connected to the VLAG peers appear to be a single trunk that is
connected to a single logical device.
The VLAG-capable switches synchronize their logical view of the access layer port structure
and internally prevent implicit loops. The VLAG topology also responds more quickly to link
failure and does not result in unnecessary MAC flooding.
As shown in Figure 2-7, VLAG helps to avoid blocked ports by STP and allows higher
performance and full redundancy.
Figure 2-7 Comparing STP with blocked ports versus VLAG loop-free topology
vLAG domain
CORE
SWITCH 1
CORE
SWITCH 2
ACCESS
SWITCH
vLAG peer link
vLAG
LACP
LACP LACP
Spanning Tree domain
CORE
SWITCH 1
CORE
SWITCH 2
ACCESS
SWITCH
LACP
LACP LACP
LACP
LACP
Blocked Port
Using STP: blocked ports Using VLAG: loop-free – no blocked port
Important: The protocol for VLAG peer links is not standardized, so the switches in a pair
of switches must belong to the same product family.

2.4.3 Cisco Virtual Port Channel
On the Nexus platform, Cisco implemented the VLAG concept as a version of a Multichassis
EtherChannel (MEC), called the Virtual Port Channel (vPC), as shown in Figure 2-8. The
vPC combines the advantages of hardware redundancy and the loop management of an
aggregated link. The pair of switches that is building the vPC appear to any
Portchannel-attached device as a single switch from Layer 2 perspective, while they are still
operating as two independent devices with independent switch control and management.
If a vPC is used, the STP is not needed to manage the loops. Therefore, it could be disabled
on these links and all disadvantages of the STP could be eliminated. The biggest advantage
of this configuration is the usability of all bandwidth of the installed links and the fast handling
of link failures within the vPC.
Figure 2-8 Schematic drawing of vPC
The pair of switches that is building the vPC is seen as a single switch from the device that is
connected to the Port channel. This device can be a server, a switch, or any other network
device.
2.4.4 Link Layer Discovery Protocol: 802.1AB
The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link-layer protocol that is used
by network devices to enable standardized discovery of network nodes.
LLDP performs functions similar to several proprietary protocols, such as the Cisco Discovery
Protocol (CDP).
vPC domain
CORE
SWITCH 1
CORE
SWITCH 2
ACCESS
SWITCH
vPC peer link
vPC
LACP
Spanning Tree domain
CORE
SWITCH 1
CORE
SWITCH 2
ACCESS
SWITCH
LACP
LACP LACP
LACP
LACP
Blocked Port
Using STP: blocked ports Using vPC: no blocked port
vPC peer link

Chapter 3. IBM RackSwitch G8264
connectivity
In this chapter, various network configuration scenarios for a PureSystem that is connected to
an IBM Rack Switch infrastructure are described.
Configuration tests have been done for commonly used network technologies, VLAN trunking
(IEEE 802.1Q), static and dynamic link aggregation (LACP), Spanning Tree (PVRST, MSTP),
and network virtualization with VLAG (virtual Link Aggregation).
Link Layer Discovery Protocol (LLDP) as vendor independent protocol is used to verify Layer
2 topology.
In this chapter, we show the configuration dumps of the network devices and the commands
that are used to verify the proper operation of the switches. We explain the configurations with
use cases that show examples of how to configure the devices for this setup.
򐂰 Prerequisites
򐂰 Use Case 1: PVRST
򐂰 Use Case 2: Link aggregation and PVRST
򐂰 Use Case 3: Link aggregation and MST
򐂰 Use Case 4: Link aggregation, MSTP and VLAG
򐂰 Use Case 5: Link aggregation and VLAG without STP
3

3.1 Prerequisites
We started by physically connecting a triangle with two IBM RackSwitch™ G8264 switches
and one IBM Flex System™ EN2092 1 Gb switch. We configured four VLANs and set up Per
VLAN Rapid Spanning Tree (PVSTP). To test connectivity, we used a test PC.
We used the following switches and one PC to test connectivity:
򐂰 Two IBM RackSwitch G8264 switches
򐂰 One IBM Flex System EN2092 1 Gb Ethernet Scalable Switch
򐂰 One test PC
The links between the switches always are 10 Gigabit Ethernet.
3.2 Use Case 1: PVRST
In Use Case 1, we have a pair of IBM RackSwitch G8264 switches connected to Flex System
EN2092 1-Gb Ethernet Scalable Switch with PVRST.
In this use case, we used three 10 GE links to connect the switches. We also configured
802.1q trunks and PVRST. For load balancing, odd VLANs 10 and 30 and even VLANs 20
and 40 are used, as shown in Figure 3-1 (odd VLANs) and Figure 3-2 on page 17 (even
VLANs)
Figure 3-1 Use Case 1: PVRST: Odd-numbered VLANs
Use Case 1: PVRSTP : G6284 to EN2092 1 Gb Ethernet Scalable
Switch, STP State for odd VLANs 10, 30
Port 17
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:G8264_1
G8264
hostname:G8264_2
G8264
hostname:Flex
EN2092 1 Gb Ethernet Switch
Pure Flex System
STP Root
Vlan 10,30
Port 63
Vlan 10,30
Port State: FWD
Port Role: DESG
Port 63
Vlan 20,40
Port State: FWD
Port Role: DESG
Port 17
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext22
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext21
Vlan 10,30
Port State: DISC
Port Role: ALTN
Test-PC
Ext4

Chapter 3. IBM RackSwitch G8264 connectivity 17
Figure 3-2 Use Case 1: PVRST: Even-numbered VLANs
Switch, STP State for even VLANs 20, 40
Port 17
Vlan 20,40
Port State: FWD
Port Role: ROOT
hostname:G8264_1
G8264
hostname:G8264_2
G8264
hostname:Flex
Pure Flex System
Port 63
Vlan 20,40
Port State: FWD
Port Role: DESG
Port 63
Vlan 20,40
Port State: FWD
Port Role: DESG
Port 17
Vlan 20,40
Port State: FWD
Port Role: DESG
Ext22
Vlan 20,40
Port State: DISC
Port Role: ALTN
Ext21
Vlan 20,40
Port State: FWD
Port Role: ROOT
Test-PC
Ext4
STP Root
Vlan 20,40

3.2.1 Verifying the topology by using lldp
To verify the topology, we used the lldp remote-device command on the three switches, as
shown in Example 3-1. Important parameters and details are highlighted in red.
Example 3-1 Checking the topology use show lldp remote-device
Flex#sh lldp remote-device
LLDP Remote Devices Information
LocalPort | Index | Remote Chassis ID | Remote Port | Remote System Name
----------|-------|---------------------------|----------------------|-------------------
EXT22 | 1 | 08 17 f4 32 bb 00 | 63 | G8264_1
EXT21 | 2 | fc cf 62 9d 67 00 | 63 | G8264_2
INTA1 | 3 | 5c f3 fc 5f 43 9d | 5c-f3-fc-5f-43-9d |
EXT5 | 6 | 00 0d ec a3 8f 81 | mgmt0 | vie
EXT7 | 7 | 00 05 9b 7b 84 01 | mgmt0 | str
!--- Display the LLDP remote devices.
!--- The local Port Numbers of the Pure Flex System Ethernet Switch
!--- distinguish between internal and external Ethernet ports.
!--- The EXT4 port connecting to the Test PC is not shown as this device does not support
LLDP .
G8264_1#show lldp remote-device
----------|-------|---------------------------|----------------------|-------------------
17 | 1 | fc cf 62 9d 67 00 | 17 | G8264_2
63 | 2 | 08 17 f4 76 78 00 | 50 | Flex
!--- The port EXT22 of the Flex switch is mapped to remote port number 50.
----------|-------|---------------------------|----------------------|-------------------
17 | 1 | 08 17 f4 32 bb 00 | 17 | G8264_1
63 | 2 | 08 17 f4 76 78 00 | 49 | Flex
!--- The port EXT21 of the Flex switch is mapped to remote port number 49.

3.2.2 Verifying trunks
To verify which VLANs are active on which trunk, we used the show interface trunk
command on the switches, as shown in Example 3-2. Important parameters and details are
highlighted in red.
Example 3-2 Output from the show interface trunk command
Flex#show interface trunk
Alias Port Tag RMON Lrn Fld PVID NAME VLAN(s)
------- ---- --- ---- --- --- ----- -------------- -------------------------------
...
EXT4 32 y d e e 1 TEST_PC 1 10 20 30 40
...
EXT21 49 y d e e 10 TO_G8264_2_Port63 10 20 30 40
EXT22 50 y d e e 10 TO_G8264_1_Port63 10 20 30 40
EXT23 51 y d e e 10 TO_G8264_1_Port64 10 20 30 40
EXT24 52 y d e e 10 TO_G8264_2_Port64 10 20 30 40
* = PVID is tagged.
G8264_2#sh int trunk
------- ---- --- ---- --- --- ----- -------------- -------------------------------
17 17 y d e e 10 CrossLink 10 20 30 40
18 18 y d e e 10 CrossLink 10 20 30 40
63 63 y d e e 10 UPLINK_TO_FLEX 10 20 30 40
* = PVID is tagged.
3.2.3 Verifying PVRST spanning tree configurations
We verified the PVRST spanning tree configuration of the switches by executing the
show spanning-tree command, which produced the following outputs. Important parameters
and details are highlighted in red:
򐂰 EN2029: Example 3-3 on page 20
򐂰 G8264 switch 1: Example 3-4 on page 22
As shown in Figure 3-1 on page 16, we have two spanning trees, one for even-numbered
VLANs and one for odd-numbered VLANs. By using the show spanning-tree command, you
can verify the status of the respective Ethernet interface’s VLAN, port state, and port role.

Example 3-3 Verifying the PVRST spanning tree configuration: EN2092 switch
Flex#sh spanning-tree
------------------------------------------------------------------
Pvst+ compatibility mode enabled
------------------------------------------------------------------
Spanning Tree Group 1: On (PVRST)
VLANs: 1
Current Root: Path-Cost Port Hello MaxAge FwdDel
8000 00:16:ca:a1:c1:00 20000 EXT3 2 20 15
Parameters: Priority Hello MaxAge FwdDel Aging Topology Change Counts
61441 2 20 15 300 3
Port Prio Cost State Role Designated Bridge Des Port Type
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
INTA1 0 0 FWD *
INTA2 0 0 FWD *
INTA4 0 0 FWD *
EXT1 128 20000! FWD DESG f001-08:17:f4:76:78:00 801d P2P
EXT2 128 20000! FWD DESG f001-08:17:f4:76:78:00 801e P2P
EXT3 128 20000! FWD ROOT 8000-00:16:ca:a1:c1:00 8011 P2P
EXT4 128 20000! FWD DESG f001-08:17:f4:76:78:00 8020 P2P
EXT5 128 20000! FWD DESG f001-08:17:f4:76:78:00 8021 P2P
EXT7 128 20000! FWD DESG f001-08:17:f4:76:78:00 8023 P2P
* = STP turned off for this port.
! = Automatic path cost.
------------------------------------------------------------------
VLANs: 10
600a 08:17:f4:32:bb:00 2000 EXT22 2 20 15
!--- Compare the ID of the Root with the LLDP output to identify the root switch.
61450 2 20 15 300 4
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f00a-08:17:f4:76:78:00 8020 P2P
EXT21 128 2000! DISC ALTN 700a-fc:cf:62:9d:67:00 803f Shared
EXT22 128 2000! FWD ROOT 600a-08:17:f4:32:bb:00 803f Shared
------------------------------------------------------------------
VLANs: 20
6014 fc:cf:62:9d:67:00 2000 EXT21 2 20 15
61460 2 20 15 300 3

------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f014-08:17:f4:76:78:00 8020 P2P
EXT21 128 2000! FWD ROOT 6014-fc:cf:62:9d:67:00 803f Shared
EXT22 128 2000! DISC ALTN 7014-08:17:f4:32:bb:00 803f Shared
------------------------------------------------------------------
VLANs: 30
601e 08:17:f4:32:bb:00 2000 EXT22 2 20 15
61470 2 20 15 300 4
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f01e-08:17:f4:76:78:00 8020 P2P
EXT21 128 2000! DISC ALTN 701e-fc:cf:62:9d:67:00 803f Shared
EXT22 128 2000! FWD ROOT 601e-08:17:f4:32:bb:00 803f Shared
------------------------------------------------------------------
VLANs: 40
6028 fc:cf:62:9d:67:00 2000 EXT21 2 20 15
61480 2 20 15 300 3
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f028-08:17:f4:76:78:00 8020 P2P
EXT21 128 2000! FWD ROOT 6028-fc:cf:62:9d:67:00 803f Shared
EXT22 128 2000! DISC ALTN 7028-08:17:f4:32:bb:00 803f Shared
------------------------------------------------------------------
Spanning Tree Group 128: Off (PVRST), FDB aging timer 300
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT1 0 0 FWD *

Example 3-4 Verifying the PVRST spanning tree configuration: G8264 switch 1
G8264_1#sh spanning-tree
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 1
8001 08:17:f4:32:bb:00 0 0 2 20 15
32769 2 20 15 300 7
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
Note: There is no active STP port in Spanning Tree Group 1.
------------------------------------------------------------------
VLANs: 10
600a 08:17:f4:32:bb:00 0 0 2 20 15
24586 2 20 15 300 3
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD DESG 600a-08:17:f4:32:bb:00 8011 P2P
63 128 2000! FWD DESG 600a-08:17:f4:32:bb:00 803f P2P
------------------------------------------------------------------
VLANs: 20
6014 fc:cf:62:9d:67:00 2000 17 2 20 15
28692 2 20 15 300 2
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD ROOT 6014-fc:cf:62:9d:67:00 8011 P2P
63 128 2000! FWD DESG 7014-08:17:f4:32:bb:00 803f P2P
------------------------------------------------------------------
VLANs: 30
601e 08:17:f4:32:bb:00 0 0 2 20 15

24606 2 20 15 300 3
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD DESG 601e-08:17:f4:32:bb:00 8011 P2P
63 128 2000! FWD DESG 601e-08:17:f4:32:bb:00 803f P2P
------------------------------------------------------------------
VLANs: 40
6028 fc:cf:62:9d:67:00 2000 17 2 20 15
28712 2 20 15 300 2
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD ROOT 6028-fc:cf:62:9d:67:00 8011 P2P
63 128 2000! FWD DESG 7028-08:17:f4:32:bb:00 803f P2P
------------------------------------------------------------------
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT 0 0 FWD *

Example 3-5 Verifying the PVRST spanning tree configuration: G8264 switch 2
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 1
8001 fc:cf:62:9d:67:00 0 0 2 20 15
32769 2 20 15 300 0
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
------------------------------------------------------------------
VLANs: 10
600a 08:17:f4:32:bb:00 2000 17 2 20 15
28682 2 20 15 300 3
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD ROOT 600a-08:17:f4:32:bb:00 8011 P2P
63 128 2000! FWD DESG 700a-fc:cf:62:9d:67:00 803f P2P
------------------------------------------------------------------
VLANs: 20
6014 fc:cf:62:9d:67:00 0 0 2 20 15
24596 2 20 15 300 2
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD DESG 6014-fc:cf:62:9d:67:00 8011 P2P
63 128 2000! FWD DESG 6014-fc:cf:62:9d:67:00 803f P2P
------------------------------------------------------------------
VLANs: 30
601e 08:17:f4:32:bb:00 2000 17 2 20 15

28702 2 20 15 300 3
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD ROOT 601e-08:17:f4:32:bb:00 8011 P2P
63 128 2000! FWD DESG 701e-fc:cf:62:9d:67:00 803f P2P
------------------------------------------------------------------
VLANs: 40
6028 fc:cf:62:9d:67:00 0 0 2 20 15
24616 2 20 15 300 2
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 128 2000! FWD DESG 6028-fc:cf:62:9d:67:00 8011 P2P
63 128 2000! FWD DESG 6028-fc:cf:62:9d:67:00 803f P2P
------------------------------------------------------------------
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT 0 0 FWD *
3.2.4 Show running-config of all switches in Use Case 1
In the configuration output of the IBM Flex Switch and the IBM rack switches that are shown in
the following examples, you can see the necessary configuration steps we did during our test.
Important parameters and details are highlighted in red:

Example 3-6 Output from show running: EN2092 switch
Flex#sh run
Current configuration:
!
version "7.2.2.2"
switch-type "IBM Flex System EN2092 1Gb Ethernet Scalable Switch"
!
…
!
hostname "Flex"
…
!
interface port INTA2
tagging
exit
!
shutdown
exit
!
interface port EXT4
name "TEST_PC"
tagging
exit
!
interface port EXT21
name "TO_G8264_2_Port63"
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
shutdown
tagging
pvid 10
exit
!
shutdown
tagging
pvid 10
exit
!
vlan 1
member INTA1-EXT20
no member EXT21-EXT24
!
!
vlan 10
enable
name "Server"
member EXT4,EXT21-EXT24

!
!
vlan 20
enable
name "Data20"
!
!
vlan 30
enable
name "Data30"
!
!
vlan 40
enable
name "Data40"
!
!
!
spanning-tree stp 10 vlan 10
!
lldp enable
!
…
!
end
Example 3-7 Output from show running command: 8264 switch 1
G8264_1#sh run
!
version "7.2.2"
switch-type "IBM Networking Operating System RackSwitch G8264"
!
!
!
!
no system dhcp
hostname "G8264_1"
system idle 60
!
!
interface port 17
name "CrossLink"
tagging
pvid 10
exit
!

interface port 18
shutdown
tagging
pvid 10
exit
!
interface port 63
tagging
pvid 10
exit
!
interface port 64
shutdown
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
!
vlan 10
enable
name "none"
member 17-18,63-64
!
!
vlan 20
enable
name "none"
member 17-18,63-64
!
!
vlan 30
enable
name "none"
member 17-18,63-64
!
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
!
spanning-tree stp 10 bridge priority 24576
!

!
lldp enable
!
…
!
end
Example 3-8 Output from show running command: G8264 switch 2
G8264_2#sh run
!
version "7.2.2"
!
!
!
!
no system dhcp
hostname "G8264_2"
system idle 60
!
!
interface port 17
name "CrossLink"
tagging
pvid 10
exit
!
interface port 18
shutdown
tagging
pvid 10
exit
!
interface port 63
tagging
pvid 10
exit
!
interface port 64
shutdown
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
!
vlan 10
enable
name "none"
member 17-18,63-64
!
!

vlan 20
enable
name "none"
member 17-18,63-64
!
!
vlan 30
enable
name "none"
member 17-18,63-64
!
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
!
!
!
lldp enable
!
…
!
!
end
3.3 Use Case 2: Link aggregation and PVRST
In our second use case, we added aggregation links and used three pairs of 10 GE links to
connect the switches. We also configured 802.1q trunks with LACP and PVRST. For load
balancing, odd VLANS 10 and 30 and even VLANS 20 and 40 were used (see Figure 3-3 on
page 31 and Figure 3-4 on page 31).

Figure 3-3 Use Case 2: Even-numbered VLANs
Figure 3-4 Use Case 2: Odd-numbered VLANs
Switch with LACP, STP State for even VLANs 20, 40
Port 17,18
Vlan 20,40
Port State: FWD
Port Role: ROOT
hostname:Flex
Pure Flex System
Port 63,64
Vlan 20,40
Port State: FWD
Port Role: DESG
Port 63,64
Vlan 20,40
Port State: FWD
Port Role: DESG
Ext22,23
Vlan 20,40
Port State: DISC
Port Role: ALTN
Ext21,24
Vlan 20,40
Port State: FWD
Port Role: ROOT
Test-PC
Ext4
STP Root
Vlan 20,40
hostname:G8264_1
G8264
hostname:G8264_2
G8264
Port 17,18
Vlan 20,40
Port State: FWD
Port Role: DESG
Switch with LACP, STP State for odd VLANs 10, 30
Port 17,18
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:Flex
Pure Flex System
Port 63,64
Vlan 10,30
Port State: FWD
Port Role: DESG
Port 63,64
Vlan 10,30
Port State: FWD
Port Role: DESG
Ext22,23
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext21,24
Vlan 10,30
Port State: DISC
Port Role: ALTN
Test-PC
Ext4
STP Root
Vlan 10,30
hostname:G8264_1
G8264
hostname:G8264_2
G8264
Port 17,18
Vlan 10,30
Port State: FWD
Port Role: ROOT

3.3.1 Verifying the topology that is used by using lldp
To verify the topology, we used the show lldp remote-device command on the three
switches, as shown in Example 3-9.
Example 3-9 Checking the topology use show lldp remote-device command
Flex#show lldp remote-device
----------|-------|---------------------------|----------------------|-------------------
EXT22 | 1 | 08 17 f4 32 bb 00 | 63 | G8264_1
EXT21 | 2 | fc cf 62 9d 67 00 | 63 | G8264_2
EXT23 | 5 | 08 17 f4 32 bb 00 | 64 | G8264_1
EXT24 | 8 | fc cf 62 9d 67 00 | 64 | G8264_2
G8264_1#sh lldp remote-device
----------|-------|---------------------------|----------------------|-------------------
17 | 1 | fc cf 62 9d 67 00 | 17 | G8264_2
63 | 2 | 08 17 f4 76 78 00 | 50 | Flex
18 | 3 | fc cf 62 9d 67 00 | 18 | G8264_2
64 | 4 | 08 17 f4 76 78 00 | 51 | Flex
----------|-------|---------------------------|----------------------|-------------------
17 | 1 | 08 17 f4 32 bb 00 | 17 | G8264_1
63 | 2 | 08 17 f4 76 78 00 | 49 | Flex
18 | 3 | 08 17 f4 32 bb 00 | 18 | G8264_1
64 | 4 | 08 17 f4 76 78 00 | 52 | Flex

command on the three switches, as shown in Example 3-10.
Example 3-10 Show interface trunk command
------- ---- --- ---- --- --- ----- -------------- -------------------------------
EXT21 49 y d e e 10 TO_G8264_2_Port63 10 20 30 40
EXT22 50 y d e e 10 TO_G8264_1_Port63 10 20 30 40
EXT23 51 y d e e 10 TO_G8264_1_Port64 10 20 30 40
EXT24 52 y d e e 10 TO_G8264_2_Port64 10 20 30 40
* = PVID is tagged.
------- ---- --- ---- --- --- ----- -------------- -------------------------------
17 17 y d e e 10 CrossLink 10 20 30 40
18 18 y d e e 10 CrossLink 10 20 30 40
...
* = PVID is tagged.
------- ---- --- ---- --- --- ----- -------------- -------------------------------
17 17 y d e e 10 CrossLink 10 20 30 40
18 18 y d e e 10 CrossLink 10 20 30 40
* = PVID is tagged.

3.3.3 Verifying link aggregation by using lacp
We verified the link aggregation configuration of the three switches by executing the
show lacp information command, as shown in Example 3-11.
Example 3-11 Show lacp information command
Flex#sh lacp information
port mode adminkey operkey selected prio aggr trunk status minlinks
---------------------------------------------------------------------------------
EXT21 active 121 121 yes 32768 49 53 up 1
EXT22 active 122 122 yes 32768 50 54 up 1
EXT23 active 122 122 yes 32768 50 54 up 1
EXT24 active 121 121 yes 32768 49 53 up 1
!--- The “aggr” and “trunk” column identifies the ports which are configured together as
link aggregation, i.e.trunk 53 is made of EXT21 and EXT24 .
G8264_1(config)#sh lacp information
---------------------------------------------------------------------------------
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
63 active 163 163 yes 32768 63 66 up 1
64 active 163 163 yes 32768 63 66 up 1
G8264_2#sh lacp information
---------------------------------------------------------------------------------
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
63 active 163 163 yes 32768 63 66 up 1
64 active 163 163 yes 32768 63 66 up 1
3.3.4 Verifying PVRST spanning tree configuration
In the next step, we verified the PVRST spanning tree configuration of the switches by
executing the show spanning-tree command. As shown in Figure 3-3 on page 31 and
Figure 3-4 on page 31, we have two spanning trees, one for even VLANs and one for odd
VLANs. By using the show spanning tree command, you can verify the status of the
respective Ethernet interface’s VLAN, port state, and port role.
The commands that were run on the three switches produced the following outputs:

Example 3-12 Output from show spanning tree command: Flex System switch
Flex#show spanning-tree
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 1
8000 00:16:ca:a1:c1:00 20000 EXT3 2 20 15
61441 2 20 15 300 3
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
INTA1 0 0 FWD *
INTA2 0 0 FWD *
INTA4 0 0 FWD *
EXT4 128 20000! FWD DESG f001-08:17:f4:76:78:00 8020 P2P
EXT5 128 20000! FWD DESG f001-08:17:f4:76:78:00 8021 P2P
EXT7 128 20000! FWD DESG f001-08:17:f4:76:78:00 8023 P2P
------------------------------------------------------------------
VLANs: 10
600a 08:17:f4:32:bb:00 990 EXT22 2 20 15
61450 2 20 15 300 8
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT21 (pc53) 128 990!+ DISC ALTN 700a-fc:cf:62:9d:67:00 8083 P2P
EXT22 (pc54) 128 990!+ FWD ROOT 600a-08:17:f4:32:bb:00 8083 P2P
EXT23 (pc54) 128 990!+ FWD ROOT 600a-08:17:f4:32:bb:00 8083 P2P
EXT24 (pc53) 128 990!+ DISC ALTN 700a-fc:cf:62:9d:67:00 8083 P2P
+ = Portchannel cost, not the individual port cost.
!--- Please note the portchannel identifier after the port number, i.e. pc53, pc54
------------------------------------------------------------------
VLANs: 20
6014 fc:cf:62:9d:67:00 990 EXT21 2 20 15
61460 2 20 15 300 10

------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f014-08:17:f4:76:78:00 8020 P2P
EXT21 (pc53) 128 990!+ FWD ROOT 6014-fc:cf:62:9d:67:00 8083 P2P
EXT22 (pc54) 128 990!+ DISC ALTN 7014-08:17:f4:32:bb:00 8083 P2P
------------------------------------------------------------------
VLANs: 30
601e 08:17:f4:32:bb:00 990 EXT22 2 20 15
61470 2 20 15 300 8
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT21 (pc53) 128 990!+ DISC ALTN 701e-fc:cf:62:9d:67:00 8083 P2P
EXT22 (pc54) 128 990!+ FWD ROOT 601e-08:17:f4:32:bb:00 8083 P2P
EXT23 (pc54) 128 990!+ FWD ROOT 601e-08:17:f4:32:bb:00 8083 P2P
EXT24 (pc53) 128 990!+ DISC ALTN 701e-fc:cf:62:9d:67:00 8083 P2P
------------------------------------------------------------------
VLANs: 40
6028 fc:cf:62:9d:67:00 990 EXT21 2 20 15
61480 2 20 15 300 10
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f028-08:17:f4:76:78:00 8020 P2P
------------------------------------------------------------------
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT1 0 0 FWD *

Example 3-13 Output from show spanning tree command: G8264 switch 1
G8264_1(config)#sh spanning-tree
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 1
8001 08:17:f4:32:bb:00 0 0 2 20 15
32769 2 20 15 300 7
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
!--- Note: There is no active STP port in Spanning Tree Group 1.
------------------------------------------------------------------
VLANs: 10
600a 08:17:f4:32:bb:00 0 0 2 20 15
24586 2 20 15 300 7
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD DESG 600a-08:17:f4:32:bb:00 8082 P2P
------------------------------------------------------------------
VLANs: 20
6014 fc:cf:62:9d:67:00 990 17 2 20 15
28692 2 20 15 300 9
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD ROOT 6014-fc:cf:62:9d:67:00 8082 P2P
63 (pc66) 128 990!+ FWD DESG 7014-08:17:f4:32:bb:00 8083 P2P
64 (pc66) 128 990!+ FWD DESG 7014-08:17:f4:32:bb:00 8083 P2P

------------------------------------------------------------------
VLANs: 30
601e 08:17:f4:32:bb:00 0 0 2 20 15
24606 2 20 15 300 7
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD DESG 601e-08:17:f4:32:bb:00 8082 P2P
------------------------------------------------------------------
VLANs: 40
6028 fc:cf:62:9d:67:00 990 17 2 20 15
28712 2 20 15 300 9
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
63 (pc66) 128 990!+ FWD DESG 7028-08:17:f4:32:bb:00 8083 P2P
64 (pc66) 128 990!+ FWD DESG 7028-08:17:f4:32:bb:00 8083 P2P
------------------------------------------------------------------

Example 3-14 Output from show spanning tree command: G8264 switch 2
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 1
8001 fc:cf:62:9d:67:00 0 0 2 20 15
32769 2 20 15 300 0
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
------------------------------------------------------------------
VLANs: 10
600a 08:17:f4:32:bb:00 990 17 2 20 15
28682 2 20 15 300 6
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD ROOT 600a-08:17:f4:32:bb:00 8082 P2P
18 (pc65) 128 990!+ FWD ROOT 600a-08:17:f4:32:bb:00 8082 P2P
63 (pc66) 128 990!+ FWD DESG 700a-fc:cf:62:9d:67:00 8083 P2P
64 (pc66) 128 990!+ FWD DESG 700a-fc:cf:62:9d:67:00 8083 P2P
------------------------------------------------------------------
VLANs: 20
6014 fc:cf:62:9d:67:00 0 0 2 20 15
24596 2 20 15 300 9
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD DESG 6014-fc:cf:62:9d:67:00 8082 P2P
------------------------------------------------------------------

VLANs: 30
601e 08:17:f4:32:bb:00 990 17 2 20 15
28702 2 20 15 300 6
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD ROOT 601e-08:17:f4:32:bb:00 8082 P2P
18 (pc65) 128 990!+ FWD ROOT 601e-08:17:f4:32:bb:00 8082 P2P
63 (pc66) 128 990!+ FWD DESG 701e-fc:cf:62:9d:67:00 8083 P2P
64 (pc66) 128 990!+ FWD DESG 701e-fc:cf:62:9d:67:00 8083 P2P
------------------------------------------------------------------
VLANs: 40
6028 fc:cf:62:9d:67:00 0 0 2 20 15
24616 2 20 15 300 9
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
------------------------------------------------------------------
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT 0 0 FWD *

In the configuration output of the switches that is shown in Example 3-15, Example 3-16 on
page 43, and Example 3-17 on page 45, you can see the configuration steps that we
performed during our test. Important parameters and detail are highlighted in red.
Example 3-15 Output of the show running command: EN2092 switch
Flex#sh run
!
version "7.2.2.2"
!
hostname "Flex"
!
tagging
exit
!
shutdown
exit
!
interface port EXT4
name "TEST_PC"
tagging
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
vlan 1
member INTA1-EXT20
!
vlan 10
enable
name "Server"

!
vlan 20
enable
name "Data20"
!
vlan 30
enable
name "Data30"
!
vlan 40
enable
name "Data40"
!
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 122
!
lacp mode active
lacp key 122
!
lacp mode active
lacp key 121
!
lldp enable
!
end

Example 3-16 Output of the show running command: G8264 switch 1
G8264_1#sh run
!
version "7.2.2"
!
hostname "G8264_1"
!
interface port 17
name "CrossLink"
tagging
pvid 10
exit
!
interface port 18
name "CrossLink"
tagging
pvid 10
exit
!
interface port 63
name "UPLINK_TO_FLEX"
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
vlan 10
enable
name "none"
member 17-18,63-64
!
vlan 20
enable
name "none"
member 17-18,63-64
!
vlan 30
enable
name "none"
member 17-18,63-64
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!

!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
lldp enable
!
end

G8264_2#sh run
!
version "7.2.2"
!
hostname "G8264_2"
!
interface port 17
name "CrossLink"
tagging
pvid 10
exit
!
interface port 18
name "CrossLink"
tagging
pvid 10
exit
!
interface port 63
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
vlan 10
enable
name "none"
member 17-18,63-64
!
vlan 20
enable
name "none"
member 17-18,63-64
!
vlan 30
enable
name "none"
member 17-18,63-64
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!

!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
lldp enable
!
end

3.4 Use Case 3: Link aggregation and MST
For this use case, we replaced the PVRST with MST. Again, we have three pairs of 10 GE
links between the three switches, which were running 802.1q trunking and LACP. The VLANs
10 and 30, and 20 and 40 are manually distributed over the uplinks from the Flex switch, as
shown in Figure 3-5 and Figure 3-6 on page 48.
Use Case 3: MSTP : G6284 to EN2092 1 Gb Ethernet Scalable
Switch with LACP, STP State for even VLANs 20, 40
Port 17,18
Vlan 20,40
Port State: FWD
Port Role: ROOT
hostname:Flex
Pure Flex System
Port 63,64
Vlan 20,40
Port State: FWD
Port Role: DESG
Port 63,64
Vlan 20,40
Port State: FWD
Port Role: DESG
Ext22,23
Vlan 20,40
Port State: DISC
Port Role: ALTN
Ext21,24
Vlan 20,40
Port State: FWD
Port Role: ROOT
Test-PC
Ext4
STP Root
Vlan 20,40
hostname:G8264_1
G8264
hostname:G8264_2
G8264
Port 17,18
Vlan 20,40
Port State: FWD
Port Role: DESG

Use Case 3: MSTP : G6284 to EN2092 1 Gb Ethernet Scalable
Switch with LACP, STP State for odd VLANs 10, 30
Port 17,18
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:Flex
Pure Flex System
Port 63,64
Vlan 10,30
Port State: FWD
Port Role: DESG
Port 63,64
Vlan 10,30
Port State: FWD
Port Role: DESG
Ext22,23
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext21,24
Vlan 10,30
Port State: DISC
Port Role: ALTN
Test-PC
Ext4
STP Root
Vlan 10,30
hostname:G8264_1
G8264
hostname:G8264_2
G8264
Port 17,18
Vlan 10,30
Port State: FWD
Port Role: ROOT

3.4.1 Verifying the topology that was used by using lldp
To verify the topology, we used the show lldp remote-device command on the switches, as
shown in Example 3-18.
Example 3-18 Checking the topology use show lldp remote-device command
----------|-------|---------------------------|----------------------|-------------------------------
EXT22 | 1 | 08 17 f4 32 bb 00 | 63 | G8264_1
EXT21 | 2 | fc cf 62 9d 67 00 | 63 | G8264_2
EXT23 | 5 | 08 17 f4 32 bb 00 | 64 | G8264_1
EXT24 | 8 | fc cf 62 9d 67 00 | 64 | G8264_2
----------|-------|---------------------------|----------------------|-------------------------------
17 | 1 | fc cf 62 9d 67 00 | 17 | G8264_2
63 | 2 | 08 17 f4 76 78 00 | 50 | Flex
18 | 3 | fc cf 62 9d 67 00 | 18 | G8264_2
64 | 4 | 08 17 f4 76 78 00 | 51 | Flex
----------|-------|---------------------------|----------------------|-------------------------------
17 | 1 | 08 17 f4 32 bb 00 | 17 | G8264_1
63 | 2 | 08 17 f4 76 78 00 | 49 | Flex
18 | 3 | 08 17 f4 32 bb 00 | 18 | G8264_1
64 | 4 | 08 17 f4 76 78 00 | 52 | Flex

command on the switches, as shown in Example 3-19.
Example 3-19 Show interface trunk command
Flex#sh interface trunk
------- ---- --- ---- --- --- ----- -------------- -------------------------------
EXT21 49 y d e e 10 TO_G8264_2_Port63 10 20 30 40
EXT22 50 y d e e 10 TO_G8264_1_Port63 10 20 30 40
EXT23 51 y d e e 10 TO_G8264_1_Port64 10 20 30 40
EXT24 52 y d e e 10 TO_G8264_2_Port64 10 20 30 40
* = PVID is tagged.
G8264_1#sh interface trunk
------- ---- --- ---- --- --- ----- -------------- -------------------------------
16 16 n d e e 1 1
17 17 y d e e 10 CrossLink 10 20 30 40
18 18 y d e e 10 CrossLink 10 20 30 40
* = PVID is tagged.
------- ---- --- ---- --- --- ----- -------------- -------------------------------
17 17 y d e e 10 CrossLink 10 20 30 40
18 18 y d e e 10 CrossLink 10 20 30 40
* = PVID is tagged.

3.4.3 Verifying link aggregation by using lacp
We verified the link aggregation configuration of the switches by executing the show lacp
information command, as shown in Example 3-20.
Example 3-20 Show lacp information command
Flex#sh lacp info
---------------------------------------------------------------------------------
EXT21 active 121 121 yes 32768 49 53 up 1
EXT22 active 122 122 yes 32768 50 54 up 1
EXT23 active 122 122 yes 32768 50 54 up 1
EXT24 active 121 121 yes 32768 49 53 up 1
---------------------------------------------------------------------------------
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
63 active 163 163 yes 32768 63 66 up 1
64 active 163 163 yes 32768 63 66 up 1
---------------------------------------------------------------------------------
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
63 active 163 163 yes 32768 63 66 up 1
64 active 163 163 yes 32768 63 66 up 1
3.4.4 Verifying MST spanning tree configuration
In the next step, we verified the MST spanning tree configuration of the switches by executing
the show spanning-tree command. As shown in Figure 3-5 on page 47 and Figure 3-6 on
page 48, we have two spanning trees, one for even VLANs and one for odd VLANs. By using
the show spanning tree command, you can verify the status of the respective Ethernet
interface’s VLAN, port state, and port role.

Example 3-21 Verifying the MST spanning tree configuration: Flex System switch
------------------------------------------------------------------
Mstp Digest: 0xe821ccee7501115289b37c79a72e07c9
------------------------------------------------------------------
Spanning Tree Group 1: On (MSTP)
VLANs MAPPED: 10 30
VLANs: 10 30
Current Root: Path-Cost Port
6000 08:17:f4:32:bb:00 990 EXT22
Parameters: Priority Aging Topology Change Counts
61440 300 4
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f000-08:17:f4:76:78:00 8020 P2P
EXT21 (pc53) 128 990!+ DISC ALTN 7000-fc:cf:62:9d:67:00 8083 P2P
EXT22 (pc54) 128 990!+ FWD ROOT 6000-08:17:f4:32:bb:00 8083 P2P
EXT23 (pc54) 128 990!+ FWD ROOT 6000-08:17:f4:32:bb:00 8083 P2P
EXT24 (pc53) 128 990!+ DISC ALTN 7000-fc:cf:62:9d:67:00 8083 P2P
------------------------------------------------------------------
VLANs MAPPED: 20 40
VLANs: 20 40
6000 fc:cf:62:9d:67:00 990 EXT21
61440 300 6
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f000-08:17:f4:76:78:00 8020 P2P

Example 3-22 Verifying the MST spanning tree configuration: G8264 switch 1
------------------------------------------------------------------
------------------------------------------------------------------
VLANs MAPPED: 10 30
VLANs: 10 30
6000 08:17:f4:32:bb:00 0 0
24576 300 8
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD DESG 6000-08:17:f4:32:bb:00 8082 P2P
18 (pc65) 128 990!+ FWD DESG 6000-08:17:f4:32:bb:00 8082 P2P
63 (pc66) 128 990!+ FWD DESG 6000-08:17:f4:32:bb:00 8083 P2P
64 (pc66) 128 990!+ FWD DESG 6000-08:17:f4:32:bb:00 8083 P2P
------------------------------------------------------------------
VLANs MAPPED: 20 40
VLANs: 20 40
6000 fc:cf:62:9d:67:00 990 17
28672 300 8Press q to quit, any other key to
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
63 (pc66) 128 990!+ FWD DESG 7000-08:17:f4:32:bb:00 8083 P2P
64 (pc66) 128 990!+ FWD DESG 7000-08:17:f4:32:bb:00 8083 P2P

Example 3-23 Verifying the MST spanning tree configuration: G8264 switch 2
------------------------------------------------------------------
------------------------------------------------------------------
VLANs MAPPED: 10 30
VLANs: 10 30
6000 08:17:f4:32:bb:00 990 17
28672 300 2
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD ROOT 6000-08:17:f4:32:bb:00 8082 P2P
18 (pc65) 128 990!+ FWD ROOT 6000-08:17:f4:32:bb:00 8082 P2P
------------------------------------------------------------------
VLANs MAPPED: 20 40
VLANs: 20 40
6000 fc:cf:62:9d:67:00 0 0
24576 300 6Press q to quit, any other key to
------------- ---- ---------- ----- ---- ---------------------- -------- ----------

In the configuration output of the switches that is shown in Example 3-24, you can see the
necessary configuration steps that we performed during our test. Important parameters and
detail are highlighted in red.
򐂰 EN2029: Example 3-24
Flex#sh run
!
version "7.2.2.2"
!
hostname "Flex"
!
tagging
exit
!
shutdown
exit
!
interface port EXT4
name "TEST_PC"
tagging
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
vlan 1

member INTA1-EXT20
!
vlan 10
enable
name "Server"
!
vlan 20
enable
name "Data20"
!
vlan 30
enable
name "Data30"
!
vlan 40
enable
name "Data40"
!
spanning-tree mstp version 10
spanning-tree mstp name "PureFlex"
spanning-tree mode mst
spanning-tree mstp cist-add-vlan 1
!
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 122
!
lacp mode active
lacp key 122
!
lacp mode active
lacp key 121
!
lldp enable
!
End

G8264_1#sh run
!
version "7.2.2"
!
hostname "G8264_1"
!
!
interface port 17
name "CrossLink"
tagging
pvid 10
exit
!
interface port 18
name "CrossLink"
tagging
pvid 10
exit
!
interface port 63
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
vlan 10
enable
name "none"
member 17-18,63-64
!
vlan 20
enable
name "none"
member 17-18,63-64
!
vlan 30
enable
name "none"
member 17-18,63-64
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!

!
!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
lldp enable
!
end
G8264_2#sh run
!
version "7.2.2"
!
hostname "G8264_2"
!
interface port 17
name "CrossLink"
tagging
pvid 10
exit
!
interface port 18
name "CrossLink"
tagging
pvid 10
exit
!

interface port 63
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
vlan 10
enable
name "none"
member 17-18,63-64
!
vlan 20
enable
name "none"
member 17-18,63-64
!
vlan 30
enable
name "none"
member 17-18,63-64
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!

interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
lldp enable
!
end
3.5 Use Case 4: Link aggregation, MSTP and VLAG
The concept of virtual link aggregation (VLAG) shows the pair of G8264 switches logically as
one switch entity. Together with LACP, this configuration allows the typical triangle design to
be run, as shown in Figure 3-7.
Figure 3-7 VLAG with MST
Figure 3-8 on page 61 shows the logical view of the setup. To the IBM Flex Switch, the pair of
IBM RackSwitch G8264 switches looks like one switch.
Use Case 4: Virtual Link Aggregation with MST: IBM G8264 to
EN2092 Ethernet Scalable Switch (physical view)
hostname:G8264_2
IBM G8264
hostname:G8264_1
IBM G8264
Port 63-64 Port 63-64
Test-PC
Ext4
Ext21, Ext24
lacp key 121
Port State: FWD
Port Role: ROOT
Ext22, Ext23
lacp key 121
Port State: FWD
Port Role: ROOT
Port 17-18 Port 17-18
pc66
pc66
pc65
vLAG ISL trunk
pc53
vLAG key 163
MGT: 192.168.240.40/24
MGT: 192.168.240.50/24
vLAG tier-id 256 vLAG healthcheck link
hostname:Flex
EN2092 Ethernet Switch
PureFlex System

Figure 3-8 VLAG with MST (logical view)
Use Case 4: Virtual Link Aggregation with MST: IBM G8264 to
EN2092 Ethernet Scalable Switch (logical view)
Logical Switch
IBM G8264(s)
Test-PC
Ext4
Ext21, Ext24
lacp key 121
Ext22, Ext23
lacp key 121
pc53
hostname:Flex
PureFlex System
logical view
PureFlex System
pc66

Example 3-27 Verifying the topology by using lldp
----------|-------|---------------------------|----------------------|--------------------
17 | 1 | fc cf 62 9d 67 00 | 17 | G8264_2
63 | 2 | 08 17 f4 76 78 00 | 50 | Flex
18 | 3 | fc cf 62 9d 67 00 | 18 | G8264_2
64 | 4 | 08 17 f4 76 78 00 | 51 | Flex
----------|-------|---------------------------|----------------------|------------------
17 | 1 | 08 17 f4 32 bb 00 | 17 | G8264_1
63 | 2 | 08 17 f4 76 78 00 | 49 | Flex
18 | 3 | 08 17 f4 32 bb 00 | 18 | G8264_1
64 | 4 | 08 17 f4 76 78 00 | 52 | Flex
----------|-------|---------------------------|----------------------|-------------------
EXT22 | 1 | 08 17 f4 32 bb 00 | 63 | G8264_1
EXT21 | 2 | fc cf 62 9d 67 00 | 63 | G8264_2
INTA4 | 4 | 5c f3 fc 6e 23 41 | 5c-f3-fc-6e-23-41 |
EXT23 | 5 | 08 17 f4 32 bb 00 | 64 | G8264_1
EXT7 | 7 | 00 05 9b 7b 84 01 | mgmt0 | str
EXT24 | 8 | fc cf 62 9d 67 00 | 64 | G8264_2
3.5.2 Verify interface status
To verify the interface, we used the show interface status command on the switches, as
Example 3-28 Verify interface status
G8264_1#sh interface st
------------------------------------------------------------------
Alias Port Speed Duplex Flow Ctrl Link Name
------- ---- ----- -------- --TX-----RX-- ------ ------
1 1 10000 full no no down 1
--
17 17 10000 full no no up CrossLink
19 19 1G/10G full no no down 19
--

63 63 10000 full no no up UPLINK_TO_FLEX
MGT 65 1000 full yes yes up MGT
G8264_2#sh interface status
------------------------------------------------------------------
------- ---- ----- -------- --TX-----RX-- ------ ------
--
--
Flex#show interface status
------------------------------------------------------------------
------- ---- ----- -------- --TX-----RX-- ------ ------
INTA1 1 1000 full yes yes up INTA1
INTA3 3 1000 full yes yes down INTA3
INTA7 7 1000 full yes yes disabled INTA7
INTB1 15 1000 full yes yes down INTB1
--
EXT1 29 1000 full no no up EXT1
EXT4 32 1000 full no no up TEST_PC
--
EXT20 48 any any no no down EXT20
EXT21 49 10000 full no no up TO_G8264_2_Port63
MGT1 53 1000 full no no up MGT1

Example 3-29 Verifying trunks
------- ---- --- ---- --- --- ----- -------------- -------------------------------
1 1 n d e e 1 1
--
16 16 n d e e 1 1
17 17 y d d e 4094 CrossLink 10 20 30 40 4094
18 18 y d d e 4094 CrossLink 10 20 30 40 4094
19 19 n d e e 1 1
--
62 62 n d e e 1 1
MGT 65 n d e e 4095 4095
------- ---- --- ---- --- --- ----- -------------- -------------------------------
1 1 n d e e 1 1
--
16 16 n d e e 1 1
17 17 y d d e 4094 CrossLink 10 20 30 40 4094
18 18 y d d e 4094 CrossLink 10 20 30 40 4094
19 19 n d e e 1 1
--
62 62 n d e e 1 1
MGT 65 n d e e 4095 4095
------- ---- --- ---- --- --- ----- -------------- -------------------------------
INTA1 1 n d e e 1 INTA1 1
INTA2 2 y d e e 1 INTA2 1
INTB1 15 n d e e 1 INTB1 1
--
EXT1 29 n d e e 1 EXT1 1

EXT4 32 y d e e 1 TEST_PC 1 10 20 30 40
--
EXT20 48 n d e e 1 EXT20 1
EXT21 49 y d e e 10 TO_G8264_2_Port63 10 20 30 40
EXT22 50 y d e e 10 TO_G8264_1_Port63 10 20 30 40
EXT23 51 y d e e 10 TO_G8264_1_Port64 10 20 30 40
EXT24 52 y d e e 10 TO_G8264_2_Port64 10 20 30 40
MGT1 53 y d e e 4095 MGT1 4095
3.5.4 Verify spanning tree
We verified the spanning tree configuration of the switches by executing the
show spanning-tree command, as shown in Example 3-30.
Example 3-30 Verify spanning tree
------------------------------------------------------------------
------------------------------------------------------------------
VLANs MAPPED: 10 30
VLANs: 10 30
6000 08:17:f4:32:bb:00 0 0
24576 300 20
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 128 990!+ FWD DESG 6000-08:17:f4:32:bb:00 8082 P2P
18 (pc65) 128 990!+ FWD DESG 6000-08:17:f4:32:bb:00 8082 P2P
63 (pc66) 128 200!+ FWD DESG 6000-08:17:f4:32:bb:00 8102 P2P
64 (pc66) 128 200!+ FWD DESG 6000-08:17:f4:32:bb:00 8102 P2P
------------------------------------------------------------------
VLANs MAPPED: 20 40
VLANs: 20 40
6000 fc:cf:62:9d:67:00 990 17
28672 300 19
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
63 (pc66) 128 200!+ FWD DESG 7000-08:17:f4:32:bb:00 8102 P2P

64 (pc66) 128 200!+ FWD DESG 7000-08:17:f4:32:bb:00 8102 P2P
------------------------------------------------------------------
Spanning Tree Group 32: Off (MSTP), FDB aging timer 300
VLANs MAPPED: 4094
VLANs: 4094
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
17 (pc65) 0 0 FWD *
18 (pc65) 0 0 FWD *
3.5.5 Verify virtual link aggregation
We verified the link aggregation configuration of the switches by executing various show
commands, as shown in Example 3-31.
Example 3-31 Verify virtual link aggregation
G8264_1#show lacp information
---------------------------------------------------------------------------------
1 off 1 1 no 32768 -- -- -- 1
--
16 off 16 16 no 32768 -- -- -- 1
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
19 off 19 19 no 32768 -- -- -- 1
--
62 off 62 62 no 32768 -- -- -- 1
63 active 163 163 yes 32768 63 66 up 1
64 active 163 163 yes 32768 63 66 up 1
G8264_1#sh lacp aggregator 63
Aggregator Id 63
----------------------------------------------
Aggregator MAC address - 08:17:f4:32:bb:a0
Actor System Priority - 32768
Actor System ID - 08:17:f4:c3:dd:ff
Individual - FALSE
Actor Oper Key - 163
Partner System Priority - 32768
Partner System ID - 08:17:f4:76:78:00
Partner Oper Key - 121
ready - TRUE
Min-Links - 1
Number of Ports in aggr - 2
index 0 port 63
index 1 port 64
G8264_1#show vlag adminkey 163
vLAG is enabled on admin key 163
Current LACP params for 63: active, Priority 32768, Admin Key 163, Min-Links 1

G8264_1#show vlag information
vLAG Tier ID: 256
vLAG system MAC: 08:17:f4:c3:dd:ff
Local MAC 08:17:f4:32:bb:00 Priority 0 Admin Role PRIMARY (Operational Role PRIMARY)
Peer MAC fc:cf:62:9d:67:00 Priority 0
Health local 192.168.240.40 peer 192.168.240.50 State UP
ISL trunk id 65
ISL state Up
Startup Delay Interval: 120s (Finished)
vLAG 65: config with admin key 163, associated trunk 66, state formed
G8264_1#show vlag isl
ISL_ID ISL_Vlan ISL_Trunk ISL_Members Link_State Trunk_State
65 4094 Adminkey 117 17 UP UP
18 UP UP
G8264_1#show vlag statistics
vLAG PDU sent:
Role Election: 2 System Info: 1
Peer Instance Enable: 2 Peer Instance Disable: 0
FDB Dynamic Add: 4 FDB Dynamic Del: 4
FDB Inactive Add: 0 FDB Inactive Del: 0
Health Check: 384 ISL Hello: 31
Other: 0 Unknown: 0
vLAG PDU received:
Other: 0 Unknown: 0
vLAG IGMP packets forwarded:
IGMP Reports: 0
IGMP Leaves: 0
---------------------------------------------------------------------------------
1 off 1 1 no 32768 -- -- -- 1
--
16 off 16 16 no 32768 -- -- -- 1
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
19 off 19 19 no 32768 -- -- -- 1
--
62 off 62 62 no 32768 -- -- -- 1
63 active 163 163 yes 32768 64 66 up 1
64 active 163 163 yes 32768 64 66 up 1
G8264_2#show lacp aggregator 64
Aggregator Id 64
----------------------------------------------
Aggregator MAC address - fc:cf:62:9d:67:a0

Individual - FALSE
ready - TRUE
Min-Links - 1
index 0 port 63
index 1 port 64
G8264_2#sh vlag information
vLAG Tier ID: 256
Local MAC fc:cf:62:9d:67:00 Priority 0 Admin Role SECONDARY (Operational Role SECONDARY)
Peer MAC 08:17:f4:32:bb:00 Priority 0
ISL trunk id 65
ISL state Up
G8264_2#sh vlag adminkey 163
G8264_2#sh vlag isl
18 UP UP
G8264_2#sh vlag statistics
vLAG PDU sent:
Other: 0 Unknown: 0
vLAG PDU received:
Other: 0 Unknown: 0
IGMP Reports: 0
IGMP Leaves: 0

---------------------------------------------------------------------------------
INTA1 off 1 1 no 32768 -- -- -- 1
--
INTB14 off 28 28 no 32768 -- -- -- 1
EXT1 off 29 29 no 32768 -- -- -- 1
--
EXT20 off 48 48 no 32768 -- -- -- 1
EXT21 active 121 121 yes 32768 52 53 up 1
EXT22 active 121 121 yes 32768 52 53 up 1
EXT23 active 121 121 yes 32768 52 53 up 1
EXT24 active 121 121 yes 32768 52 53 up 1
Flex#sh lacp
Current LACP system ID: 08:17:f4:76:78:00
Current LACP system Priority: 32768
Current LACP timeout scale: long
Current LACP params for EXT21: active, Priority 32768, Admin Key 121, Min-Links 1
Flex#sh lacp aggregator 52
Aggregator Id 52
----------------------------------------------
Aggregator MAC address - 08:17:f4:76:78:86
Actor System ID - 08:17:f4:76:78:00
Individual - FALSE
Partner System ID - 08:17:f4:c3:dd:ff
ready - TRUE
Min-Links - 1
index 0 port EXT21
index 1 port EXT22
index 2 port EXT23
index 3 port EXT24
The Flex switch now has one aggregated link (port channel) consisting of four connections to
the logically unified pair of IBM G8264 switches. Previously, the Flex switch featured two
aggregated links that consisted of two connections each to two separate IBM G8264.
The MST spanning tree is still configured. In contrast to the configurations without VLAG, all
four ports now are in spanning tree status forwarding because they all belong to the same
LCAP channel.

The following configuration memory dumps of the three switches show the successfully tested
setup. The essential parameters for this use case are highlighted in red.
Flex#sh run
!
version "7.2.2.2"
!
!
snmp-server user 4 name "DirectorServerSNMPv3User"
snmp-server user 4 authentication-protocol sha authentication-password
"602e911d40088008ac26f2f683b823fa38bbdaca61af87e7367acc3d627979a016507d179fd43edc664137aa7e
2b40f63d"
snmp-server user 4 privacy-protocol des privacy-password
"7f068e355a008a20b62ee7f699b029d28afa8626040f6b48106531c7dcf753ad33117273b4a73403720bee4701
1b065f9c"
!
snmp-server group 4 user-name DirectorServerSNMPv3User
snmp-server group 4 group-name "ibmd_grp_4"
!
snmp-server access 4 name "ibmd_grp_4"
snmp-server access 4 level authPriv
snmp-server access 4 notify-view "iso"
!
snmp-server target-address 1 name "ibmd_taddr_1" address 192.168.10.103
snmp-server target-address 1 parameters-name "ibmd_tparam_1"
!
snmp-server target-parameters 1 name "ibmd_tparam_1"
snmp-server target-parameters 1 user-name "DirectorServerSNMPv3User"
snmp-server target-parameters 1 level authPriv
!
snmp-server version v1v2v3
!
snmp-server name "Flex"
!
hostname "Flex"
system idle 60
!
!
access http enable
access telnet enable
!
tagging
exit
!
shutdown
exit

!
interface port EXT4
name "TEST_PC"
tagging
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
vlan 1
member INTA1-EXT20
!
!
vlan 10
enable
name "Server"
!
!
vlan 20
enable
name "Data20"
!
!
vlan 30
enable
name "Data30"
!
!
vlan 40
enable
name "Data40"
!
!
!

!
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
!
!
!
!
!
lldp enable
!
!
!
!
!
ntp enable
ntp ipv6 primary-server fe80::211:25ff:fec3:1420 MGT
ntp interval 15
ntp authenticate
ntp primary-key 49909
!
ntp message-digest-key 103 md5-ekey
4264b3504204a200ae2df2b381b401f2d384e6827376b623d79c78c89f3b4288a2619aa3f05c0d5dc8a369a956a
81063a4203a5a34993a54288393f9264b42da
!
! SNIP
! …more lines of “ntp message-digest-key”
! SNIP
!
f42d0519500d0008bc24e6f293bda3fadbbc2899f01c55d586637020e1f9dd332028f2e1b627438abbd5bbe8350
5dc965b43752daacb2751446c122610608374
!
ntp trusted-key
103,1821,2416,3343,4617,6903,7255,9094,10386,10939,12266,12389,13261,13280,13640,14424,1641

7,17555,17944,18537,19291,19742,19776,20027,21166,21710,22141,22512,23917,25162,25988,27418
,27687,27964,28200,29005,29180,29297,29395,31615,31972,32287,32782,34183,35544,35571,37155,
37414,37968,38424,38865,38947,39752,40976,41343,41997,42080,42261,42816,42898,43020,48745,4
9909,50872,51266,54111,54278,55616,57966,61370,62043,62789,63696,63785,64175,64248
!
end
G8264_1#sh run
version "7.2.2"
!
!
!
!
no system dhcp
hostname "G8264_1"
system idle 60
!
!
interface port 17
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 18
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 63
name "DOWNLINK_TO_FLEX"
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
!
vlan 10
enable
name "none"
member 17-18,63-64
!
!
vlan 20

enable
name "none"
member 17-18,63-64
!
!
vlan 30
enable
name "none"
member 17-18,63-64
!
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
vlan 4094
enable
name "VLAG_ISL"
member 17-18
!
!
!
!
no spanning-tree stp 32 enable
!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
!

!
vlag enable
vlag tier-id 256
vlag isl vlan 4094
vlag hlthchk peer-ip 192.168.240.50
vlag isl adminkey 117
vlag adminkey 163 enable
!
!
!
!
!
!
!
!
!
!
lldp enable
!
interface ip 128
ip address 192.168.240.40
enable
exit
!
ip gateway 4 address 192.168.240.1
ip gateway 4 enable
!
!
end
G8264_2#sh run
!
version "7.2.2"
!
!
!
!
no system dhcp
hostname "G8264_2"
system idle 60
!
!
interface port 17
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 18
name "CrossLink"
tagging
pvid 4094
exit

!
interface port 63
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
!
vlan 10
enable
name "none"
member 17-18,63-64
!
!
vlan 20
enable
name "none"
member 17-18,63-64
!
!
vlan 30
enable
name "none"
member 17-18,63-64
!
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
vlan 4094
enable
name "VLAG_ISL"
member 17-18
!
!
!
!

!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
!
!
vlag enable
vlag tier-id 256
vlag isl vlan 4094
!
!
!
!
!
!
!
!
!
!
lldp enable
!
interface ip 128
ip address 192.168.240.50
enable
exit
!
ip gateway 4 enable
!
!
!
!
!
!
end

3.6 Use Case 5: Link aggregation and VLAG without STP
The concept of virtual link aggregation (VLAG) shows the pair of G8264 switch logically as
one switch entity. Together with LACP, this configuration allows the typical triangle design to
be run, as shown in Figure 3-9, without spanning tree.
Figure 3-9 Use Case 5
Use Case 5: Virtual Link Aggregation: IBM G8264 to IBM Flex
System EN2092 Ethernet Scalable Switch (physical view)
hostname:G8264_2
IBM G8264
hostname:G8264_1
IBM G8264
Port 63-64 Port 63-64
Test-PC
Ext4
Ext21, Ext24
lacp key 121
Ext22, Ext23
lacp key 121
Port 17-18 Port 17-18
pc66
pc66
pc65
vLAG ISL trunk
vLAG key 163
MGT: 192.168.240.40/24
MGT: 192.168.240.50/24
vLAG tier-id 256 vLAG healthcheck link
hostname:Flex
PureFlex System
pc53

Example 3-35 Verifying the topology by using lldp
----------|-------|---------------------------|----------------------|-------------------
17 | 1 | fc cf 62 9d 67 00 | 17 | G8264_2
63 | 2 | 08 17 f4 76 78 00 | 50 | Flex
18 | 3 | fc cf 62 9d 67 00 | 18 | G8264_2
64 | 4 | 08 17 f4 76 78 00 | 51 | Flex
----------|-------|---------------------------|----------------------|-------------------
17 | 1 | 08 17 f4 32 bb 00 | 17 | G8264_1
63 | 2 | 08 17 f4 76 78 00 | 49 | Flex
18 | 3 | 08 17 f4 32 bb 00 | 18 | G8264_1
64 | 4 | 08 17 f4 76 78 00 | 52 | Flex
----------|-------|---------------------------|----------------------|-------------------
EXT22 | 1 | 08 17 f4 32 bb 00 | 63 | G8264_1
EXT21 | 2 | fc cf 62 9d 67 00 | 63 | G8264_2
INTA4 | 4 | 5c f3 fc 6e 23 41 | 5c-f3-fc-6e-23-41 |
EXT23 | 5 | 08 17 f4 32 bb 00 | 64 | G8264_1
EXT7 | 7 | 00 05 9b 7b 84 01 | mgmt0 | str
EXT24 | 8 | fc cf 62 9d 67 00 | 64 | G8264_2
3.6.2 Verify interface status
To verify the interface, we used the show interface status command on the switches, as
Example 3-36 Verify interface status
G8264_1#sh int status
------------------------------------------------------------------
------- ---- ----- -------- --TX-----RX-- ------ ------
--
--

G8264_2#show interface status
------------------------------------------------------------------
------- ---- ----- -------- --TX-----RX-- ------ ------
--
--
Flex#sh interface status
------------------------------------------------------------------
------- ---- ----- -------- --TX-----RX-- ------ ------
INTA7 7 1000 full yes yes disabled INTA7
--
EXT4 32 1000 full no no up TEST_PC
--
EXT20 48 any any no no down EXT20

Example 3-37 Verifying trunks
------- ---- --- ---- --- --- ----- -------------- -------------------------------
1 1 n d e e 1 1
--
16 16 n d e e 1 1
17 17 y d d e 4094 CrossLink 10 20 30 40 4094
18 18 y d d e 4094 CrossLink 10 20 30 40 4094
19 19 n d e e 1 1
--
62 62 n d e e 1 1
MGT 65 n d e e 4095 4095
------- ---- --- ---- --- --- ----- -------------- -------------------------------
1 1 n d e e 1 1
--
16 16 n d e e 1 1
17 17 y d d e 4094 CrossLink 10 20 30 40 4094
18 18 y d d e 4094 CrossLink 10 20 30 40 4094
19 19 n d e e 1 1
--
62 62 n d e e 1 1
MGT 65 n d e e 4095 4095
------- ---- --- ---- --- --- ----- -------------- -------------------------------
INTA2 2 y d e e 1 INTA2 1
--

EXT4 32 y d e e 1 TEST_PC 1 10 20 30 40
--
EXT20 48 n d e e 1 EXT20 1
EXT21 49 y d e e 10 TO_G8264_2_Port63 10 20 30 40
EXT22 50 y d e e 10 TO_G8264_1_Port63 10 20 30 40
EXT23 51 y d e e 10 TO_G8264_1_Port64 10 20 30 40
EXT24 52 y d e e 10 TO_G8264_2_Port64 10 20 30 40
MGT1 53 y d e e 4095 MGT1 4095
3.6.4 Verify virtual link aggregation
We verified the link aggregation configuration of the switches by executing various show
commands, as shown in Example 3-38.
Example 3-38 Verify virtual link aggregation
G8264_1#show lacp information
---------------------------------------------------------------------------------
1 off 1 1 no 32768 -- -- -- 1
--
16 off 16 16 no 32768 -- -- -- 1
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
19 off 19 19 no 32768 -- -- -- 1
--
62 off 62 62 no 32768 -- -- -- 1
63 active 163 163 yes 32768 63 66 up 1
64 active 163 163 yes 32768 63 66 up 1
Aggregator Id 63
----------------------------------------------
Aggregator MAC address - 08:17:f4:32:bb:a0
Individual - FALSE
ready - TRUE
Min-Links - 1
index 0 port 63
index 1 port 64
G8264_1#show spanning-tree
Spanning Tree is shut down.
G8264_1#sh vlag
vLAG status: enabled
vLAG Tier ID: 256
Local Priority: 0
ISL Information: VLAN 4094, Trunk 0, LACP Key 117
Health check Peer IP Address: 192.168.240.50
Health check connection retry interval: 30 seconds

Health check number of keepalive attempts: 3
Health check keepalive interval: 5 seconds
vLAG startup delay interval: 120 seconds
Current LACP system ID: 08:17:f4:32:bb:00
vLAG 65 : active
vLAG Tier ID: 256
Local MAC 08:17:f4:32:bb:00 Priority 0 Admin Role PRIMARY (Operational Role SECONDARY)
Peer MAC fc:cf:62:9d:67:00 Priority 0
ISL trunk id 65
ISL state Up
G8264_1#sh vlag isl
18 UP UP
vLAG PDU sent:
Other: 0 Unknown: 0
vLAG PDU received:
Other: 0 Unknown: 0
IGMP Reports: 0
IGMP Leaves: 0

---------------------------------------------------------------------------------
1 off 1 1 no 32768 -- -- -- 1
--
16 off 16 16 no 32768 -- -- -- 1
17 active 117 117 yes 32768 17 65 up 1
18 active 117 117 yes 32768 17 65 up 1
19 off 19 19 no 32768 -- -- -- 1
--
62 off 62 62 no 32768 -- -- -- 1
63 active 163 163 yes 32768 64 66 up 1
64 active 163 163 yes 32768 64 66 up 1
Aggregator Id 64
----------------------------------------------
Aggregator MAC address - fc:cf:62:9d:67:a0
Individual - FALSE
ready - TRUE
Min-Links - 1
index 0 port 63
index 1 port 64
G8264_2#sh vlag
vLAG status: enabled
vLAG Tier ID: 256
Local Priority: 0
ISL Information: VLAN 4094, Trunk 0, LACP Key 117
Health check Peer IP Address: 192.168.240.40
Health check connection retry interval: 30 seconds
Health check number of keepalive attempts: 3
Health check keepalive interval: 5 seconds
vLAG startup delay interval: 120 seconds
Current LACP system ID: fc:cf:62:9d:67:00
vLAG 65 : active
vLAG Tier ID: 256
Local MAC fc:cf:62:9d:67:00 Priority 0 Admin Role SECONDARY (Operational Role PRIMARY)
Peer MAC 08:17:f4:32:bb:00 Priority 0
ISL trunk id 65
ISL state Up

G8264_2#sh vlag adminkey 163
G8264_2#sh vlag isl
18 UP UP
vLAG PDU sent:
Other: 0 Unknown: 0
vLAG PDU received:
Other: 0 Unknown: 0
IGMP Reports: 0
IGMP Leaves: 0
Flex#show lacp information
---------------------------------------------------------------------------------
INTA1 off 1 1 no 32768 -- -- -- 1
--
INTB14 off 28 28 no 32768 -- -- -- 1
EXT1 off 29 29 no 32768 -- -- -- 1
--
EXT20 off 48 48 no 32768 -- -- -- 1
EXT21 active 121 121 yes 32768 52 53 up 1
EXT22 active 121 121 yes 32768 52 53 up 1
EXT23 active 121 121 yes 32768 52 53 up 1
EXT24 active 121 121 yes 32768 52 53 up 1
Aggregator Id 52
----------------------------------------------
Individual - FALSE

Partner System ID - 08:17:f4:c3:dd:ff
ready - TRUE
Min-Links - 1
index 0 port EXT21
index 1 port EXT22
index 2 port EXT23
index 3 port EXT24
The Flex System switch now has one aggregated link (port channel) consisting of four
connections to the logically unified pair of IBM G8264 switches. Previously, the Flex System
switch featured two aggregated links that consisted of two connections each to two separate
IBM G8264.
The following configuration memory dumps of the IBM Flex Switch and both IBM System
Network switches show the successfully tested setup. The essential parameters for this use
case are highlighted in red.
Example 3-39 Output of the show running command: EN2092
Flex#sh run
!
version "7.2.2.2"
!
!
snmp-server user 4 name "DirectorServerSNMPv3User"
snmp-server user 4 authentication-protocol sha authentication-password
"448edc340000882085a7b7f7c3b02bd2f0520e931ea46bc5b7eded9972fe826e1a0ef96428215042c04724d220
c902acd9"
snmp-server user 4 privacy-protocol des privacy-password
"453edd840110888084b7b6e7c2a02b7269f0ab694f0b3fefcd1dc2cefc9b2755a977e48dffb7f2c02ae685e8fd
38cfc425"
!
snmp-server group 4 user-name DirectorServerSNMPv3User
snmp-server group 4 group-name "ibmd_grp_4"
!
snmp-server access 4 name "ibmd_grp_4"
snmp-server access 4 level authPriv
snmp-server access 4 notify-view "iso"
!
snmp-server target-address 1 name "ibmd_taddr_1" address 192.168.10.103
snmp-server target-address 1 parameters-name "ibmd_tparam_1"
!
snmp-server target-parameters 1 name "ibmd_tparam_1"
snmp-server target-parameters 1 user-name "DirectorServerSNMPv3User"

snmp-server target-parameters 1 level authPriv
!
snmp-server version v1v2v3
!
snmp-server name "Flex"
!
hostname "Flex"
system idle 60
!
!
access http enable
!
tagging
exit
!
shutdown
exit
!
interface port EXT4
name "TEST_PC"
tagging
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
vlan 1
member INTA1-EXT20
!
!
vlan 10
enable
name "Server"
!

!
vlan 20
enable
name "Data20"
!
!
vlan 30
enable
name "Data30"
!
!
vlan 40
enable
name "Data40"
!
!
!
spanning-tree mode disable
!
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
!
!
!
!
!
lldp enable
!
!
!
!
!
ntp enable
ntp ipv6 primary-server fe80::211:25ff:fec3:1420 MGT

ntp interval 15
ntp authenticate
ntp primary-key 49909
!
0b87933c0300822886a6f2f7c0b021da71fedfcb71dca85400f52051d4db341ddc66d383102dc917aa13d6f2967
b6179f6d9396a95503e6e0217d9f7248c1c3a
!
! SNIP
! …more lines of “ntp message-digest-key”
! SNIP
!
898311380100002884a6f2f3c2b0a3dae66cc6e9326e294b602f8fc11ca24cca6780d1f7d5b707d49f028be5635
b0932ffcfc8aa484922018dc0863fb346e37a
!
ntp trusted-key
103,1821,2416,3343,4617,6903,7255,9094,10386,10939,12266,12389,13261,13280,13640,14424,1641
7,17555,17944,18537,19291,19742,19776,20027,21166,21710,22141,22512,23917,25162,25988,27418
,27687,27964,28200,29005,29180,29297,29395,31615,31972,32287,32782,34183,35544,35571,37155,
37414,37968,38424,38865,38947,39752,40976,41343,41997,42080,42261,42816,42898,43020,48745,4
9909,50872,51266,54111,54278,55616,57966,61370,62043,62789,63696,63785,64175,64248
!
end
G8264_1#sh run
!
version "7.2.2"
!
!
!
!
no system dhcp
hostname "G8264_1"
system idle 60
!
!
interface port 17
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 18
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 63
tagging
pvid 10

exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
!
vlan 10
enable
name "none"
member 17-18,63-64
!
!
vlan 20
enable
name "none"
member 17-18,63-64
!
!
vlan 30
enable
name "none"
member 17-18,63-64
!
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
vlan 4094
enable
name "VLAG_ISL"
member 17-18
!
!
!
!
!

interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
!
!
vlag enable
vlag tier-id 256
vlag isl vlan 4094
!
!
!
!
!
!
!
!
!
!
lldp enable
!
interface ip 128
ip address 192.168.240.40
enable
exit
!
ip gateway 4 enable
!
!
end

G8264_2#sh run
!
version "7.2.2"
!
!
!
!
no system dhcp
hostname "G8264_2"
system idle 60
!
!
interface port 17
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 18
name "CrossLink"
tagging
pvid 4094
exit
!
interface port 63
tagging
pvid 10
exit
!
interface port 64
tagging
pvid 10
exit
!
vlan 1
member 1-16,19-62
no member 17-18,63-64
!
!
vlan 10
enable
name "none"
member 17-18,63-64
!
!
vlan 20
enable
name "none"
member 17-18,63-64
!
!
vlan 30
enable
name "none"

member 17-18,63-64
!
!
vlan 40
enable
name "VLAN 40"
member 17-18,63-64
!
!
vlan 4094
enable
name "VLAG_ISL"
member 17-18
!
!
!
!
!
interface port 17
lacp mode active
lacp key 117
!
interface port 18
lacp mode active
lacp key 117
!
interface port 63
lacp mode active
lacp key 163
!
interface port 64
lacp mode active
lacp key 163
!
!
!
vlag enable
vlag tier-id 256
vlag isl vlan 4094
!
!
!
!

!
!
!
!
!
!
lldp enable
!
interface ip 128
ip address 192.168.240.50
enable
exit
!
ip gateway 4 enable
!
!
!
!
!
!
end

Chapter 4. Cisco Nexus 5000 connectivity
In this chapter, we describe the process that was used to test the Layer 2 interoperability
between Cisco Nexus 5000 Switches and the embedded IBM Flex System switch. The
embedded IBM Flex Switch was connected to two Cisco Nexus 5000 switches.
We tested Layer 2 connectivity trunking, channeling (link aggregation), and spanning tree. For
trunking, we used 802.1q. For link aggregation, we tested static and LACP. The tested
spanning trees were PVRST and MSTP. To show load balancing (even if spanning tree is
active), we configured even and odd VLANS. Finally, we tested vPC to activate all of the links.
To verify Layer 2 topology, we used Link Layer Discovery Protocol (LLDP) as the vendor
independent protocol.
򐂰 Prerequisites
򐂰 Use Case 1: PVRST
򐂰 Use Case 2: PVRST with LACP Channeling
򐂰 Use Case 3: MST with LACP Channeling
򐂰 Use Case 4: MST with LACP Channeling and vPC
򐂰 Use Case 5: LACP Channeling and vPC without spanning tree
4
Important: IBM switches do not support the proprietary Cisco Discovery Protocol (CDP)
protocol.

4.1 Prerequisites
We started by physically connecting a triangle with two Cisco Nexus 5000 switches and one
IBM Systems Networking embedded Flex Switch. We configured four VLANs and set up Per
VLAN Rapid Spanning Tree (PVRST). To test connectivity, we used a test PC.
We used the following switches and one PC to test connectivity:
򐂰 One Cisco Nexus 5010 Switch
򐂰 One Cisco Nexus 5020 Switch
򐂰 One IBM Flex System EN2092 1-Gb Ethernet Scalable Switch
򐂰 One test PC
All of the links between the switches are 10 Gigabit Ethernet.
4.2 Use Case 1: PVRST
In our first use case, we used three 10 GE links to connect the switches. We also configured
802.1q trunks and PVRST. For load balancing, odd VLANs 10 and 30, and even VLANs 20
and 40 are used, as shown in Figure 4-1.
4.2.1 Verifying the topology that is used by using lldp
To verify our configurations, we used several show commands on the IBM and Cisco
switches, as shown in Example 4-1 on page 97. The essential parameters for this use case
are highlighted in red.
To check the topology, we used the show lldp remote-device command on the IBM Flex
System switch and the show lldp neighbors command on the Cisco Nexus switch. The
important parameters and details are highlighted in red.
Use Case 1: PVRSTP : Cisco Nexus 5000 to IBM Flex
System EN2092 Ethernet Scalable Switch
Eth 1/19
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
hostname:Flex
Pure Flex System
STP Root
Vlan 10,30
Ext24 Ext22
Test-PC
Ext4
Eth 1/39
STP Root
Vlan 20,40
Eth 1/1 Eth 1/1
Eth 1/19

Chapter 4. Cisco Nexus 5000 connectivity 97
Example 4-1 Verifying configurations
----------|-------|---------------------------|----------------------|-----
EXT22 | 1 | 00 0d ec a3 8f 88 | Eth1/1 | vie
EXT24 | 2 | 00 05 9b 7b 84 08 | Eth1/1 | str
!--- Display the LLDP remote devices. Note that you must enable
!--- “feature lldp” on the N5000.
!--- The local Port Numbers of the Pure Flex System Ethernet Switch
!--- distinguish between internal and external Ethernet ports.
str# show lldp neighbors
Capability codes:
(R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device
(W) WLAN Access Point, (P) Repeater, (S) Station, (O) Other
Device ID Local Intf Hold-time Capability Port ID
Flex Eth1/1 120 BR 52
vie Eth1/19 120 B Eth1/39
Total entries displayed: 2
!--- The Port named EXT22 at the Pure Flex System Ethernet Switch has the
!--- port ID 52 which is shown in the show lldp neighbors here.
vie# show lldp neighbors
Capability codes:
str Eth1/39 120 B Eth1/19
!--- The Port named EXT24 at the Pure Flex System Ethernet Switch has the
!--- port ID 50 which is shown in the show lldp neighbors here.
Port EXT22 = Port ID 50

command on the IBM Flex System switch and the Cisco Nexus switch, as shown in
Example 4-2. The important parameters and details are highlighted in red.
Example 4-2 Output of show interface trunk command
------- ---- --- ---- --- --- ----- -------------- -----------------
...
EXT4 32 y d e e 1 TEST_PC 1 10 20 30 40
...
EXT22 50 y d e e 10 TO_VIE_ETH1/1 10 20 30 40
...
EXT24 52 y d e e 10 TO_STR_ETH1/1 10 20 30 40
str# show interface trunk
--------------------------------------------------------------------------------
Port Native Status Port
Vlan Channel
--------------------------------------------------------------------------------
Eth1/1 10 trunking --
--------------------------------------------------------------------------------
Port Vlans Allowed on Trunk
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 1-3967,4048-4093
Eth1/19 1-3967,4048-4093
Eth1/20 1-3967,4048-4093
--------------------------------------------------------------------------------
Port Vlans Err-disabled on Trunk
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/19 none
Eth1/20 none
--------------------------------------------------------------------------------
Port STP Forwarding
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 none
Eth1/19 1,10,20,30,40
Eth1/20 none
--------------------------------------------------------------------------------
Port Vlans in spanning tree forwarding state and not pruned
--------------------------------------------------------------------------------
Eth1/1 --
Eth1/2 --
Eth1/19 --

Eth1/20 --
vie# show interface trunk
--------------------------------------------------------------------------------
Vlan Channel
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 1-3967,4048-4093
Eth1/39 1-3967,4048-4093
Eth1/40 1-3967,4048-4093
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/39 none
Eth1/40 none
--------------------------------------------------------------------------------
Port STP Forwarding
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 none
Eth1/39 1,10,20,30,40
Eth1/40 none
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 --
Eth1/2 --
Eth1/39 --
Eth1/40 --
As shown in Figure 4-2 on page 100 and Figure 4-3 on page 100, we have two spanning
trees, one for even-numbered VLANs and one for odd-numbered VLANs. By using the show
spanning tree command, you can verify the status of the respective Ethernet interface’s
VLAN, port state, and port role.

executing the show spanning-tree command.
Use Case 1: PVRSTP : Nexus 5000 to EN2092 Ethernet
Scalable Switch, STP State for odd VLANs 10, 30
Eth 1/19
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
hostname:Flex
Pure Flex System
STP Root
Vlan 10,30
Eth 1/1
Vlan 10,30
Port State: FWD
Port Role: DESG
Eth 1/1
Vlan 10,30
Port State: FWD
Port Role: DESG
Eth 1/39
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext24
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext22
Vlan 10,30
Port State: DISC
Port Role: ALTN
Test-PC
Ext4
Use Case 1: PVRSTP : Nexus 5000 to EN2092 Ethernet
Scalable Switch, STP State for even VLANs 20, 40
Eth 1/19
Vlan 20,40
Port State: FWD
Port Role: ROOT
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
hostname:Flex
Pure Flex System
Eth 1/1
Vlan 20,40
Port State: FWD
Port Role: DESG
Eth 1/1
Vlan 20,40
Port State: FWD
Port Role: DESG
Eth 1/39
Vlan 20,40
Port State: FWD
Port Role: DESG
Ext24
Vlan 20,40
Port State: DISC
Port Role: ALTN
Ext22
Vlan 20,40
Port State: FWD
Port Role: ROOT
Test-PC
Ext4
STP Root
Vlan 20,40

򐂰 Flex System EN2029: Example 4-3
򐂰 G8264 STR switch: Example 4-4 on page 102
򐂰 G8264 VIE switch: Example 4-5 on page 104
Important parameters and details are highlighted in red.
Example 4-3 Outout of show spanning-tree command: Flex System switch
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 10
600a 00:05:9b:7b:84:3c 2000 EXT24 2 20 15
!--- Compare the ID of the Root with the LLDP output to identify the root switch.
61450 2 20 15 300 12Press q to
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT22 128 2000! DISC ALTN 700a-00:0d:ec:a3:8f:bc 8081 P2P
EXT24 128 2000! FWD ROOT 600a-00:05:9b:7b:84:3c 8081 P2P
------------------------------------------------------------------
VLANs: 20
6014 00:0d:ec:a3:8f:bc 2000 EXT22 2 20 15
61460 2 20 15 300 1
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! DISC DESG f014-08:17:f4:76:78:00 8020 P2P
EXT22 128 2000! FWD ROOT 6014-00:0d:ec:a3:8f:bc 8081 P2P
EXT24 128 2000! DISC ALTN 7014-00:05:9b:7b:84:3c 8081 P2P
------------------------------------------------------------------
VLANs: 30
601e 00:05:9b:7b:84:3c 2000 EXT24 2 20 15
61470 2 20 15Press q to quit, any other key to cont 300
1

------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! DISC DESG f01e-08:17:f4:76:78:00 8020 P2P
EXT22 128 2000! DISC ALTN 701e-00:0d:ec:a3:8f:bc 8081 P2P
EXT24 128 2000! FWD ROOT 601e-00:05:9b:7b:84:3c 8081 P2P
------------------------------------------------------------------
VLANs: 40
6028 00:0d:ec:a3:8f:bc 2000 EXT22 2 20 15
61480 2 20 15 300 1
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! DISC DESG f028-08:17:f4:76:78:00 8020 P2P
EXT22 128 2000! FWD ROOT 6028-00:0d:ec:a3:8f:bc 8081 P2P
EXT24 128 2000! DISC ALTN 7028-00:05:9b:7b:84:3c 8081 P2P
------------------------------------------------------------------
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT1 0 0 FWD *
Example 4-4 Output of show spanning-tree command: STR switch
str# show spanning-tree
VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 32769
Address 0005.9b7b.843c
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth1/19 Desg FWD 2 128.147 P2p
VLAN0010

!--- Compare the address (ID) of the Root with the LLDP output to identify the root switch
.
---------------- ---- --- --------- -------- --------------------------------
VLAN0020
Address 000d.eca3.8fbc
Cost 2
Port 147 (Ethernet1/19)
---------------- ---- --- --------- -------- --------------------------------
Eth1/19 Root FWD 2 128.147 P2p
VLAN0030
---------------- ---- --- --------- -------- --------------------------------
VLAN0040
Cost 2

---------------- ---- --- --------- -------- --------------------------------
Example 4-5 Output of show spanning-tree command: VIE switch
vie# show spanning-tree
VLAN0001
Cost 2
---------------- ---- --- --------- -------- --------------------------------
VLAN0010
Cost 2
---------------- ---- --- --------- -------- --------------------------------
VLAN0020
---------------- ---- --- --------- -------- --------------------------------

VLAN0030
Cost 2
---------------- ---- --- --------- -------- --------------------------------
VLAN0040
---------------- ---- --- --------- -------- --------------------------------
vie#
In the following configuration print outs of the IBM Flex System switch and the Cisco Nexus
switches, you can comprehend the necessary configuration steps we did during our test.
Important parameters and detail are highlighted in red.
򐂰 Flex System EN2029: Example 4-6 on page 106
Important: Sections of the configuration output in Example 4-6 on page 106, Example 4-7
on page 108, and Example 4-8 on page 109 were removed to highlight the important parts
of the outputs. The omissions are indicated by “...”.

Example 4-6 Output of show running-config command: Flex System switch
Flex# show running-config
!
version "7.2.2.2"
!
!
…
hostname "Flex"
system idle 60
!
!
access http enable
!
…
interface port EXT4
name "TEST_PC"
tagging
exit
!
…
tagging
pvid 10
exit
!
name "TO_VIE_ETH1/1"
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
name "TO_STR_ETH1/1"
tagging
pvid 10
exit
!
vlan 1
member INTA1-EXT20
!
!
vlan 10
enable
name "Server"
!
!
vlan 20
enable
name "Data20"

!
!
vlan 30
enable
name "Data30"
!
!
vlan 40
enable
name "Data40"
!
!
!
!
!
!
!
!
!
lldp enable
!
!
!
!
!
...
end

Example 4-7 Output of show running-config command: STR switch
str# show running-config
version 5.1(3)N2(1)
hostname str
feature telnet
no feature http-server
feature lldp
username admin password 5 $1$Oc8ULbm7$bRaCJLmRCrkJRU1DcNaaJ0 role network-admin
…
vrf context management
ip route 0.0.0.0/0 192.168.240.1
vlan 1
vlan 10
name Server
vlan 20
name Data20
vlan 30
name Data30
vlan 40
name Data40
spanning-tree vlan 10,30 priority 24576
interface Ethernet1/1
description TO_FLEX_EXT24
switchport mode trunk
switchport trunk native vlan 10
switchport trunk allowed vlan 10,20,30,40
…
description TO_VIE_ETH1/39
switchport access vlan 10
shutdown
interface mgmt0
ip address 192.168.240.30/24
clock timezone MESZ 2 0
line console
line vty
boot kickstart bootflash:/n5000-uk9-kickstart.5.1.3.N2.1.bin
boot system bootflash:/n5000-uk9.5.1.3.N2.1.bin

Example 4-8 Output of show running-config command: VIE switch
vie# show running-config
version 5.1(3)N2(1)
hostname vie
feature telnet
feature lldp
username admin password 5 $1$3QkdUbKB$s1Ytem8Ty6FfYtQc9Zs0k1 role network-admin
…
ip route 0.0.0.0/0 192.168.240.1
vlan 1
vlan 10
name Server
vlan 20
name Data20
vlan 30
name Data30
vlan 40
name Data40
…
…
interface mgmt0
no snmp trap link-status
vrf member management
ip address 192.168.240.20/24
line console
line vty

4.3 Use Case 2: PVRST with LACP Channeling
In this use case, we added a second link between each switch pair to test PVRST with LACP
channeling (see Figure 4-4).
4.3.1 Verifying the topology used by using lldp
As in Use Case 1, we verified the configurations with several show commands on the IBM
and on the Cisco switches.
A best practice to check the topology is using show lldp remote-device on the IBM Flex
System switch and show lldp neighbors on the Cisco Nexus switch. Important parameters
and detail are highlighted in red.
򐂰 Flex System EN2029: Example 4-9 on page 111
Use Case 2: PVRSTP with LACP Channeling: Nexus 5K to IBM
Flex System EN2092 Ethernet Scalable Switch
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
hostname:Flex
PureFlex System
Eth 1/1 -2 Eth 1/1-2
Test-PC
Ext4
Ext21, Ext24 Ext22, Ext23
Eth 1/19-20
Eth 1/39-40
Po3
Po2
Po1
pc53 pc54

Example 4-9 Outpput of show lldp remote-device on the Flex System switch
----------|-------|---------------------------|----------------------|------------------
EXT22 | 1 | 00 0d ec a3 8f 88 | Eth1/1 | vie
EXT24 | 2 | 00 05 9b 7b 84 08 | Eth1/1 | str
EXT21 | 4 | 00 05 9b 7b 84 09 | Eth1/2 | str
EXT23 | 5 | 00 0d ec a3 8f 89 | Eth1/2 | vie
Example 4-10 Output of show lldp neighbor on the STR switch
str# show lldp neighbour
Capability codes:
Example 4-11 Output of show lldp neighbors on the VIE switch
Capability codes:

To review which vlans are active on which trunk, we used the show interface trunk on IBM
Flex switch and on the Cisco Nexus switch.
Example 4-12 Output of show interface trunk on the Flex System switch
------- ---- --- ---- --- --- ----- -------------- -------------------------------
…
EXT4 32 y d e e 1 TEST_PC 1 10 20 30 40
…
MGT1 53 y d e e 4095 MGT1 4095

Example 4-13 Output of show interface trunk on the STR switch
--------------------------------------------------------------------------------
Vlan Channel
--------------------------------------------------------------------------------
Eth1/1 10 trnk-bndl Po2
Po1 1 trunking --
Po2 10 trunking --
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 10,20,30,40
Eth1/19 1-3967,4048-4093
Eth1/20 1-3967,4048-4093
Po1 1-3967,4048-4093
Po2 10,20,30,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/19 none
Eth1/20 none
Po1 none
Po2 none
--------------------------------------------------------------------------------
Port STP Forwarding
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/19 none
Eth1/20 none
Po1 1,10,20,30,40
Po2 10,20,30,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 --
Eth1/2 --
Eth1/19 --
Eth1/20 --
Po1 --
Po2 --

Example 4-14 Output of show interface trunk on the VIE switch
--------------------------------------------------------------------------------
Vlan Channel
--------------------------------------------------------------------------------
Po1 1 trunking --
Po3 10 trunking --
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 10,20,30,40
Eth1/39 1-3967,4048-4093
Eth1/40 1-3967,4048-4093
Po1 1-3967,4048-4093
Po3 10,20,30,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/39 none
Eth1/40 none
Po1 none
Po3 none
--------------------------------------------------------------------------------
Port STP Forwarding
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/39 none
Eth1/40 none
Po1 1,10,20,30,40
Po3 10,20,30,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 --
Eth1/2 --
Eth1/39 --
Eth1/40 --
Po1 --
Po3 --

4.3.3 Verifying PVRST spanning tree configuration
executing the show spanning-tree command. In Figure 4-5 and Figure 4-6 on page 116,
showing even and odd VLANs, you can verify the status on the respective Ethernet
interface-referring VLAN, port state, and port role.
Use Case 2: PVRSTP with LACP Channeling: Nexus 5000 to
EN2092 Ethernet Switch, STP State for even VLANs 20, 40
Eth 1/19-20
Vlan 20,40
Port State: FWD
Port Role: ROOT
hostname:Flex
Pure Flex System
Eth 1/1-2
Vlan 20,40
Port State: FWD
Port Role: DESG
Eth 1/1-2
Vlan 20,40
Port State: FWD
Port Role: DESG
Ext21, Ext24
Vlan 20,40
Port State: DISC
Port Role: ALTN
Ext22, Ext23
Vlan 20,40
Port State: FWD
Port Role: ROOT
Test-PC
Ext4
STP Root
Vlan 20,40
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
Eth 1/39-40
Vlan 20,40
Port State: FWD
Port Role: ROOT
Po1
Po2 Po3
pc53 pc54

In Example 4-15, the outputs of the show commands of the Flex System and Nexus switches
show all of the link pairs are successfully channeled with LACP. The important parameters
and details are highlighted in red.
Example 4-15 Configuration output
------------------------------------------------------------------
------------------------------------------------------------------
VLANs: 1
8000 00:16:ca:a1:c1:00 20000 EXT3 2 20 15
61441 2 20 15 300 13
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
INTA1 0 0 FWD *
INTA2 0 0 FWD *
INTA4 0 0 FWD *
EXT4 128 20000! FWD DESG f001-08:17:f4:76:78:00 8020 P2P
Use Case 3: PVRSTP with LACP Channeling: Nexus 5000 to
En2092 Ethernet Switch, STP State for odd VLANs 10, 30
Eth 1/19-20
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:Flex
Pure Flex System
Eth 1/1-2
Vlan 10,30
Port State: FWD
Port Role: DESG
Eth 1/1-2
Vlan 10,30
Port State: FWD
Port Role: DESG
Ext21, Ext24
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext22, Ext23
Vlan 10,30
Port State: DISC
Port Role: ALTN
Test-PC
Ext4
STP Root
Vlan 10,30
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
Eth 1/39-40
Vlan 10,30
Port State: FWD
Port Role: ROOT
Po1
Po2 Po3
pc53 pc54

------------------------------------------------------------------
VLANs: 10
600a 00:05:9b:7b:84:3c 990 EXT21 2 20 15
61450 2 20 15 300 28
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT21 (pc53) 128 990!+ FWD ROOT 600a-00:05:9b:7b:84:3c 9001 P2P
EXT22 (pc54) 128 990!+ DISC ALTN 700a-00:0d:ec:a3:8f:bc 9002 P2P
EXT23 (pc54) 128 990!+ DISC ALTN 700a-00:0d:ec:a3:8f:bc 9002 P2P
EXT24 (pc53) 128 990!+ FWD ROOT 600a-00:05:9b:7b:84:3c 9001 P2P
------------------------------------------------------------------
VLANs: 20
6014 00:0d:ec:a3:8f:bc 990 EXT22 2 20 15
61460 2 20 15 300 20
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f014-08:17:f4:76:78:00 8020 P2P
EXT21 (pc53) 128 990!+ DISC ALTN 7014-00:05:9b:7b:84:3c 9001 P2P
EXT22 (pc54) 128 990!+ FWD ROOT 6014-00:0d:ec:a3:8f:bc 9002 P2P
------------------------------------------------------------------
VLANs: 30
601e 00:05:9b:7b:84:3c 990 EXT21 2 20 15
61470 2 20 15 300 18
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT21 (pc53) 128 990!+ FWD ROOT 601e-00:05:9b:7b:84:3c 9001 P2P
EXT22 (pc54) 128 990!+ DISC ALTN 701e-00:0d:ec:a3:8f:bc 9002 P2P
EXT23 (pc54) 128 990!+ DISC ALTN 701e-00:0d:ec:a3:8f:bc 9002 P2P
EXT24 (pc53) 128 990!+ FWD ROOT 601e-00:05:9b:7b:84:3c 9001 P2P

------------------------------------------------------------------
VLANs: 40
6028 00:0d:ec:a3:8f:bc 990 EXT22 2 20 15
61480 2 20 15 300 20
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f028-08:17:f4:76:78:00 8020 P2P
------------------------------------------------------------------
VLANs: 4095
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
MGT1 0 0 FWD *
*= STP turned off for this port.
As shown in Example 4-15 on page 116, Ethernet interfaces EXT21-24 are bundled to
channels, in which EXT21 and EXT24 form portchannel 53 and EXT22 and EXT23 form
portchannel 54.
4.3.4 Bridge priority field in the show spanning tree output
When STP was first used, there was only one spanning tree per physical switch in which the
bridge priority was stored as a 16-bit value (0-65535). With the introduction of per VLAN
spanning tree, the need to carry the VLAN ID within the bridge priority field became apparent.
The top 4 bits were still used for the bridge priority value, but the remaining 12 bits were used
to carry the VLAN ID (1-1046).
Table 4-1 lists the 16 bits translated to decimal.
Table 4-1 Bridge priority field
If you configure the bridge priority value at Cisco IOS, you must enter a multiple of 4096 or
use the keywords root primary or root secondary. If you configure the bridge priority at IBM
OS, you can enter any value and the switch changes it to the next lower value that is divisible
by 4096. The output of the show spanning tree command is shown in Example 4-16 on
page 119 and Example 4-17 on page 120. The important parameters and details are
highlighted in red.
Usage Bridge priority: 4 bits VLAN ID: 12 bit
Bit value 32768 16384 8192 4096 2048 1024 512 256 128 64 32 16 8 4 2 1

Example 4-16 Output of show spanning-tree command
VLAN0001
VLAN0010
For VLAN 10 and other odd vlans, this bridge is the root
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 1 128.4096 P2p
VLAN0020
Cost 1
Port 4096 (port-channel1)
For VLAN 20 and other even vlans, Po1 leads to the rootbrigde (Nexus 5000 Vie)
---------------- ---- --- --------- -------- --------------------------------
Po1 Root FWD 1 128.4096 P2p
VLAN0030

---------------- ---- --- --------- -------- --------------------------------
VLAN0040
Cost 1
---------------- ---- --- --------- -------- --------------------------------
Example 4-17 Output from show spanning-tree on VIE switch
VLAN0001
Cost 1
---------------- ---- --- --------- -------- --------------------------------
VLAN0010
Cost 1

---------------- ---- --- --------- -------- --------------------------------
VLAN0020
---------------- ---- --- --------- -------- --------------------------------
VLAN0030
Cost 1
---------------- ---- --- --------- -------- --------------------------------
VLAN0040
---------------- ---- --- --------- -------- --------------------------------

In the following configuration print outs of the IBM Flex Switch and the Cisco Nexus switches,
you can see the necessary configuration steps that we performed during our test. The
Flex#sh run
!
version "7.2.2.2"
!
!
…
hostname "Flex"
system idle 60
!
!
access http enable
!
…
interface port EXT4
name "TEST_PC"
tagging
exit
!
…
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit

!
vlan 1
member INTA1-EXT20
!
!
vlan 10
enable
name "Server"
!
!
vlan 20
enable
name "Data20"
!
!
vlan 30
enable
name "Data30"
!
!
vlan 40
enable
name "Data40"
!
!
!
!
! This configures the LACP portchannels in the IBM PureFlex switch
!
lacp mode active
lacp key 2
!
lacp mode active
lacp key 3
!
lacp mode active
lacp key 3
!
lacp mode active
lacp key 2
!
!
!

!
!
!
lldp enable
!
!
!
!
!
…
end
Example 4-19 Output from the show running-config command: STR switch
str# show run
version 5.1(3)N2(1)
hostname str
feature telnet
! Enables LACP
feature lacp
feature lldp
no password strength-check
…
ip route 0.0.0.0/0 192.168.240.1
vlan 1
vlan 10
name Server
vlan 20
name Data20
vlan 30
name Data30
vlan 40
name Data40
interface port-channel1
description TO_VIE_PO1
!
!
! Configure Portchannel
!
description TO_FLEX_EXT21,EXT24

!
!Configure interface and add it to portchannel2 by use of LACP (keyword = active)
!
channel-group 2 mode active
…
interface mgmt0
ip address 192.168.240.30/24
line console
line vty

vie# show run
version 5.1(3)N2(1)
hostname vie
feature telnet
feature lacp
feature
…
ip route 0.0.0.0/0 192.168.240.1
vlan 1
vlan 10
name Server
vlan 20
name Data20
vlan 30
name Data30
vlan 40
name Data40
description TO_STR_PO1
!Configure interface and add it to portchannel3 by use of LACP (keyword = active)
…

description TO_STR_ETH1/19
…
interface mgmt0
ip address 192.168.240.20/24
line console
line vty
4.4 Use Case 3: MST with LACP Channeling
In this use case, we configured MST instead of PVRST as the spanning tree option with
LACP channeling, as shown in Figure 4-7.
Figure 4-7 Use Case 3: MST with LACP Channeling
Use Case 3: MST with LACP Channeling: Nexus 5K to
IBM Flex System EN2092 Ethernet Scalable Switch
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
hostname:Flex
PureFlex System
Eth 1/1 -2 Eth 1/1-2
Test-PC
Ext4
Ext21, Ext24 Ext22, Ext23
Eth 1/19-20
Eth 1/39-40
Po3
Po2
Po1
pc53 pc54

4.4.1 Verifying the topology used by using lldp
As in the other use cases, we verified the configurations by using several show commands on
the IBM and on the Cisco switches.
A best practice to verify the topology is the use of the show lldp remote-device command on
the IBM Flex switch and the show lldp neighbors command on the Cisco Nexus switch. First,
we verified the topology after the configuration changes were made, as shown in
Example 4-21.
Example 4-21 Verifying the configurations
----------|-------|---------------------------|----------------------|--------------------
EXT22 | 1 | 00 0d ec a3 8f 88 | Eth1/1 | vie
EXT24 | 2 | 00 05 9b 7b 84 08 | Eth1/1 | str
EXT21 | 4 | 00 05 9b 7b 84 09 | Eth1/2 | str
EXT23 | 5 | 00 0d ec a3 8f 89 | Eth1/2 | vie
str# show lldp neighbors
Capability codes:
Capability codes:
command on the IBM Flex System switch and the Cisco Nexus switch, as shown in
Example 4-22. Important parameters and details are highlighted in red.
Example 4-22 Reviewing active VLANs and trunks
------- ---- --- ---- --- --- ----- -------------- -------------------------------
...
EXT4 32 y d e e 1 TEST_PC 1 10 20 30 40
...

MGT1 53 y d e e 4095 MGT1 4095
--------------------------------------------------------------------------------
Vlan Channel
--------------------------------------------------------------------------------
Po1 1 trunking --
Po2 10 trunking --
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 10,20,30,40
Eth1/19 1-3967,4048-4093
Eth1/20 1-3967,4048-4093
Po1 1-3967,4048-4093
Po2 10,20,30,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/19 none
Eth1/20 none
Po1 none
Po2 none
--------------------------------------------------------------------------------
Port STP Forwarding
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/19 none
Eth1/20 none
Po1 1,10,20,30,40
Po2 10,30
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 --
Eth1/2 --
Eth1/19 --
Eth1/20 --
Po1 --
Po2 --

--------------------------------------------------------------------------------
Port Vlans Forwarding on FabricPath
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Vlan Channel
--------------------------------------------------------------------------------
Po1 1 trunking --
Po3 10 trunking --
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 10,20,30,40
Eth1/2 10,20,30,40
Eth1/39 1-3967,4048-4093
Eth1/40 1-3967,4048-4093
Po1 1-3967,4048-4093
Po3 10,20,30,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/39 none
Eth1/40 none
Po1 none
Po3 none
--------------------------------------------------------------------------------
Port STP Forwarding
--------------------------------------------------------------------------------
Eth1/1 none
Eth1/2 none
Eth1/39 none
Eth1/40 none
Po1 1,10,20,30,40
Po3 20,40
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Eth1/1 --
Eth1/2 --
Eth1/39 --
Eth1/40 --
Po1 --
Po3 --

Figure 4-8 shows the odd-numbered VLANs. Figure 4-9 shows the even-numbered VLANs.
Figure 4-8 Use Case 3: VLANs 10, 30
Figure 4-9 Use Case 3: VLANs 20, 40
Use Case 3: MST with LACP Channeling: Nexus 5000 to EN2092
Ethernet Scalable Switch STP State for odd VLANs 10, 30
Eth 1/19-20
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:Flex
Pure Flex System
Eth 1/1-2
Vlan 10,30
Port State: FWD
Port Role: DESG
Eth 1/1-2
Vlan 10,30
Port State: FWD
Port Role: DESG
Ext21, Ext24
Vlan 10,30
Port State: FWD
Port Role: ROOT
Ext22, Ext23
Vlan 10,30
Port State: DISC
Port Role: ALTN
Test-PC
Ext4
STP Root
Region 1
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
Eth 1/39-40
Vlan 10,30
Port State: FWD
Port Role: ROOT
Po1
Po2 Po3
pc53 pc54
STP Root
Region 2
Region 1:
Vlan 10,30
Region 2:
Vlan 20,40
STP Root
Region 2
Use Case 3: MST with LACP Channeling: Nexus 5000 to EN2092
Ethernet Scalable Switch STP State for even VLANs 20, 40
Eth 1/19-20
Vlan 10,30
Port State: FWD
Port Role: DESG
hostname:Flex
Pure Flex System
Eth 1/1-2
Vlan 20,40
Port State: FWD
Port Role: DESG
Eth 1/1-2
Vlan 20,40
Port State: FWD
Port Role: DESG
Ext21, Ext24
Vlan 20,40
Port State: FWD
Port Role: ROOT
Ext22, Ext23
Vlan 20,40
Port State: DISC
Port Role: ALTN
Test-PC
Ext4
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
Eth 1/39-40
Vlan 10,30
Port State: FWD
Port Role: ROOT
Po1
Po2 Po3
pc53 pc54
STP Root
Region 1
Region 1:
Vlan 10,30
Region 2:
Vlan 20,40

4.4.3 Verifying MST spanning tree configuration
switches, you can see the necessary configuration steps that we performed during our test.
We also add some remarks to help explain the configuration that was used.
The important parameters and details are highlighted in red. As you can see highlighted in
red, MST is enabled on all MST instances on both Nexus switches.
Example 4-23 Output of show spanning-tree command: Flex System switch
------------------------------------------------------------------
------------------------------------------------------------------
VLANs MAPPED: 10 30
VLANs: 10 30
! Now spanning-tree protocol is MST for odd vlans 10 and 30
6000 00:05:9b:7b:84:3c 990 EXT21
61440 300 2
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f000-08:17:f4:76:78:00 8020 P2P
EXT21 (pc53) 128 990!+ FWD ROOT 6000-00:05:9b:7b:84:3c 9001 P2P
EXT22 (pc54) 128 990!+ FWD DESG f000-08:17:f4:76:78:00 806b P2P
EXT23 (pc54) 128 990!+ FWD DESG f000-08:17:f4:76:78:00 806b P2P
EXT24 (pc53) 128 990!+ FWD ROOT 6000-00:05:9b:7b:84:3c 9001 P2P
! EXT 21 – 24 are portchannels. EXT21 and EXT24 formed portchannel 53, EXT 21 and EXT23
! formed portchannel 54.
------------------------------------------------------------------
VLANs MAPPED: 20 40
VLANs: 20 40
! Now spanning-tree protocol is MST for even vlans 20 and 40
6000 00:0d:ec:a3:8f:bc 990 EXT22

61440 300 1
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f000-08:17:f4:76:78:00 8020 P2P
EXT21 (pc53) 128 990!+ FWD DESG f000-08:17:f4:76:78:00 806a P2P
EXT24 (pc53) 128 990!+ FWD DESG f000-08:17:f4:76:78:00 806a P2P
! EXT 21 – 24 are portchannels. EXT21 and EXT24 formed portchannel 53, EXT 21 and EXT23
! formed portchannel 54.
Example 4-24 Output of show spanning-tree command: STR switch
MST0000
Spanning tree enabled protocol mstp
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 1000 128.4096 P2p
Po2 Desg FWD 1000 128.4097 P2p
Eth1/16 Desg FWD 2000 128.144 P2p
MST0001
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 1000 128.4096 P2p
Po2 Desg FWD 1000 128.4097 P2p
Eth1/16 Desg FWD 2000 128.144 P2p
MST0002

Cost 1000
---------------- ---- --- --------- -------- --------------------------------
Po1 Root FWD 1000 128.4096 P2p
Po2 Altn BLK 1000 128.4097 P2p
Example 4-25 Output of show spanning-tree command: VIE switch
MST0000
Cost 0
---------------- ---- --- --------- -------- --------------------------------
Po1 Root FWD 1000 128.4096 P2p
Po3 Altn BLK 1000 128.4098 P2p
Eth1/16 Desg FWD 2000 128.144 P2p
MST0001
Cost 1000
---------------- ---- --- --------- -------- --------------------------------
Po1 Root FWD 1000 128.4096 P2p
Po3 Altn BLK 1000 128.4098 P2p
Eth1/16 Desg FWD 2000 128.144 P2p

MST0002
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 1000 128.4096 P2p
Po3 Desg FWD 1000 128.4098 P2p
switches, you can see the necessary configuration steps that we performed during our test.
The important parameters and details are highlighted in red.
Flex#sh running-config
!
version "7.2.2.2"
!
!
...
hostname "Flex"
system idle 60
!
!
access http enable
!
…
interface port EXT4
name "TEST_PC"
tagging
exit
!
…
tagging
pvid 10
exit

!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
vlan 1
member INTA1-EXT20
!
!
vlan 10
enable
name "Server"
!
!
vlan 20
enable
name "Data20"
!
!
vlan 30
enable
name "Data30"
!
!
vlan 40
enable
name "Data40"
!
! Configuration Part to enable MST on the PureFlex Switch
!
!
! For odd vlans 10 and 30 we had to configure stp group 1
!
!

! For even vlans 20 and 40 we had to configure stp group 2
!
!
lacp mode active
lacp key 2
!
lacp mode active
lacp key 3
!
lacp mode active
lacp key 3
!
lacp mode active
lacp key 2
!
!
!
!
!
!
lldp enable
!
!
!
!
!
…
end
Example 4-27 Output of show running-config command: STR switch
str# show run
version 5.1(3)N2(1)
hostname str
feature telnet
feature lacp
feature lldp
ip route 0.0.0.0/0 192.168.240.1
vlan 1
vlan 10
name Server

vlan 20
name Data20
vlan 30
name Data30
vlan 40
name Data40
!
! On the Cisco Nexus switch configuration is slightly different. One the str Nexus
spanning-tree ! priority for odd vlan 10 and 10 are lower than for the even vlan 20 and 40.
This has to be vice ! versa on the vie Nexus Switch. Furthermore you have to define a name
for the MST domain.
!
spanning-tree mst 1 priority 24576
spanning-tree mst configuration
name PureFlex
revision 10
instance 1 vlan 10,30
…

interface mgmt0
ip address 192.168.240.30/24
line console
line vty
vie# show run
version 5.1(3)N2(1)
hostname vie
feature telnet
feature lacp
feature lldp
…
ip route 0.0.0.0/0 192.168.240.1
vlan 1
vlan 10
name Server
vlan 20
name Data20
vlan 30
name Data30
vlan 40
name Data40
!
! On the Cisco Nexus switch configuration is slightly different. One the vie Nexus
spanning-tree ! priority for even vlan 20 and 40 are lower than for odd vlan 10 and 30.
This has to be vice ! versa on the vie Nexus Switch. Furthermore you have to define a
name for the MST domain.
!
name PureFlex
revision 10

…
interface mgmt0
ip address 192.168.240.20/24
line console
line vty

4.5 Use Case 4: MST with LACP Channeling and vPC
To reach our goal of eliminating the spanning tree, we configured vPC on the Nexus 5000
switches. In this case, MST is still enabled. Multiple physical connections between the
switches are still channeled by using LACP, as shown in Figure 4-10.
Figure 4-10 Use Case 4: MST with LACP Channeling and vPC
4.5.1 Configuring vPC on STR
To configure vPC, the two Nexus 5000 switches are configured with a vPC peer link in
between.
To avoid an active-active scenario if there is a failure, a vPC peer keep-alive link is configured.
The MGMT Interfaces are directly connected to the out-of-band keep-alive link. The interface
that forms the channel across the Nexus 5000 switches must use the same vPC number on
both Nexus 5000 switches (vPC 5 in this case), as shown in Example 4-29 on page 142. The
Use Case 4: Virtual Portchannel with MST: Nexus 5K to IBM
Flex System EN2092 Ethernet Scalable Switch (physical view)
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
Eth 1/1 -2 Eth 1/1-2
Test-PC
Ext4
Ext21, Ext24
lacp key 5
Port State: FWD
Port Role: ROOT
Ext22, Ext23
lacp key 5
Port State: FWD
Port Role: ROOT
Eth 1/19-20 Eth 1/39-40
Po3
Po2
Po1
vpc peer-link
pc53
vPC5
mgnt0: 192.168.240.20/24
mgnt0: 192.168.240.30/24
vPC domain 54 vpc peer keep alive link
hostname:Flex
PureFlex System
pc54

Example 4-29 Use Case 4: vPC Config on STR
vpc domain 54
peer-keepalive destination 192.168.240.20 source 192.168.240.30
spanning-tree port type network
vpc peer-link
vpc 5
…
interface mgmt0
ip address 192.168.240.30/24

4.5.2 Configuring MST on the STR
The commands that are shown in Example 4-30 were used to configure MST on the STR
switch.
Example 4-30 Use Case 4: MST Config STR
name PureFlex
revision 10
4.5.3 Configuring vPC on VIE
The commands that are shown Example 4-31 were used to configure vPC on the VIE switch.
Example 4-31 Use Case 4: vPC Config VIE
vpc domain 54
peer-keepalive destination 192.168.240.30 source 192.168.240.20
spanning-tree port type network
vpc peer-link
vpc 5

…
…
interface mgmt0
ip address 192.168.240.20/24
4.5.4 Configuring MST on VIE
The commands that are shown Example 4-32 were used to configure MST on the VIE switch.
Example 4-32 Use Case 4: MST Config VIE
name PureFlex
revision 10

4.5.5 Reviewing the Flex System switch configuration
The Flex System switch is unaware of vPC. The EN2092, like any end system, sees only one
Nexus switch, as shown in Example 4-33.
Example 4-33 Use Case 4: Flex System switch
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
…
!
lacp mode active
lacp key 5
!
lacp mode active
lacp key 5
!
lacp mode active
lacp key 5
!
lacp mode active
lacp key 5
!

4.5.6 Configuring MST on the Flex System switch
The commands that are shown Example 4-34 were used to configure MST on the Flex
System switch.
Example 4-34 Use Case 4: MST Config Flex
!
4.5.7 Logical view
Figure 4-11 shows the logical view of the setup. To the end system (the IBM Flex System
switch), the two Cisco Nexus 5000 switches looks like one switch.
Figure 4-11 Use Case 4: Logical view
Use Case 4: Virtual Portchannel with MST: Nexus 5K to IBM
Flex System EN2092 Ethernet Scalable Switch (logical view)
Logical Switch
Nexus 5K(s)
Test-PC
Ext4
Ext21, Ext24
lacp key 5
Ext22, Ext23
lacp key 5
pc53
hostname:Flex
PureFlex System
logical view
PureFlex System

4.5.8 Verifying the configuration
We used the show commands that are shown in Example 4-35 to verify the vPC configuration
that was used on the Nexus 5000 switches. The output helps visualize the setup. The
Example 4-35 Use Case 4: Verify the configuration
str# show vpc peer-keepalive
vPC keep-alive status : peer is alive
--Peer is alive for : (3417) seconds, (551) msec
--Send status : Success
--Last send at : 2012.05.23 19:14:17 134 ms
--Sent on interface : mgmt0
--Receive status : Success
--Last receive at : 2012.05.23 19:14:16 992 ms
--Received on interface : mgmt0
--Last update from peer : (0) seconds, (753) msec
vPC Keep-alive parameters
--Destination : 192.168.240.20
--Keepalive interval : 1000 msec
--Keepalive timeout : 5 seconds
--Keepalive hold timeout : 3 seconds
--Keepalive vrf : management
--Keepalive udp port : 3200
--Keepalive tos : 192
str# show vpc brief
Legend:
(*) - local vPC is down, forwarding via vPC peer-link
vPC domain id : 54
Peer status : peer adjacency formed ok
Configuration consistency status: success
Per-vlan consistency status : success
Type-2 consistency status : success
vPC role : primary
Number of vPCs configured : 1
Peer Gateway : Disabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
vPC Peer-link status
---------------------------------------------------------------------
id Port Status Active vlans
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
id Port Status Consistency Reason Active vlans
------ ----------- ------ ----------- -------------------------- -----------
5 Po2 up success success 10,20,30,40
str# show vpc consistency-parameters global
Legend:

Type 1 : vPC will be suspended in case of mismatch
Name Type Local Value Peer Value
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Network Qos (Pause) 2 (F, T, F, F, F, F) (F, T, F, F, F, F)
Input Queuing (Bandwidth) 2 (50, 50, 0, 0, 0, 0) (50, 50, 0, 0, 0, 0)
Input Queuing (Absolute 2 (F, F, F, F, F, F) (F, F, F, F, F, F)
Priority)
Output Queuing (Bandwidth) 2 (50, 50, 0, 0, 0, 0) (50, 50, 0, 0, 0, 0)
Output Queuing (Absolute 2 (F, F, F, F, F, F) (F, F, F, F, F, F)
Priority)
STP Mode 1 MST MST
STP Disabled 1 None None
STP MST Region Name 1 PureFlex PureFlex
STP MST Region Revision 1 10 10
STP MST Region Instance to 1
VLAN Mapping
STP Loopguard 1 Disabled Disabled
STP Bridge Assurance 1 Enabled Enabled
STP Port Type, Edge 1 Normal, Disabled, Normal, Disabled,
BPDUFilter, Edge BPDUGuard Disabled Disabled
STP MST Simulate PVST 1 Enabled Enabled
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
Local suspended VLANs - - -
str# show vpc consistency-parameters interface po1
Note: **** Global type-1 parameters will be displayed for peer-link *****
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
STP Mode 1 MST MST
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40

str# show vpc consistency-parameters vlan
Name Type Reason Code Pass Vlans
------------- ---- ---------------------- -----------------------
STP Mode 1 success 0-4095
STP Disabled 1 success 0-4095
STP MST Region Name 1 success 0-4095
STP MST Region Revision 1 success 0-4095
STP MST Region Instance to 1 success 0-4095
VLAN Mapping
STP Loopguard 1 success 0-4095
STP Bridge Assurance 1 success 0-4095
STP Port Type, Edge 1 success 0-4095
BPDUFilter, Edge BPDUGuard
STP MST Simulate PVST 1 success 0-4095
Pass Vlans - 0-4095
str# show vpc consistency-parameters vpc 5
Legend:
------------- ---- ---------------------- -----------------------
Shut Lan 1 No No
STP Port Type 1 Default Default
STP Port Guard 1 None None
STP MST Simulate PVST 1 Default Default
lag-id 1 [(7f9b, [(7f9b,
0-23-4-ee-be-36, 8005, 0-23-4-ee-be-36, 8005,
0, 0), (8000, 0, 0), (8000,
8-17-f4-76-78-0, 5, 0, 8-17-f4-76-78-0, 5, 0,
0)] 0)]
mode 1 active active
Speed 1 10 Gb/s 10 Gb/s
Duplex 1 full full
Port Mode 1 trunk trunk
Native Vlan 1 10 10
MTU 1 1500 1500
Admin port mode 1
Allowed VLANs - 10,20,30,40 10,20,30,40
str# show vpc
Legend:
vPC domain id : 54
vPC role : primary

---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
str# show vpc 5
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
str#
4.5.9 Verifying the vPC configuration on VIE
The commands that are shown Example 4-36 were used to verify the vPC configuration of the
VIE switch.
Example 4-36 Output of show commands on VIE
vie# show vpc peer-keepalive
--Last send at : 2012.05.23 19:12:07 422 ms
--Destination : 192.168.240.30
vie# show vpc brief
Legend:
vPC domain id : 54

vPC role : secondary
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
vie# show vpc
Legend:
vPC domain id : 54
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
vie# show vpc consistency-parameters global
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)

Priority)
Priority)
STP Mode 1 MST MST
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
vie# show vpc consistency-parameters interface port-channel 1
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
STP Mode 1 MST MST
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
vie# show vpc consistency-parameters vlan
------------- ---- ---------------------- -----------------------

VLAN Mapping
Pass Vlans - 0-4095
vie# show vpc consistency-parameters vpc 5
Legend:
------------- ---- ---------------------- -----------------------
Shut Lan 1 No No
lag-id 1 [(7f9b, [(7f9b,
0-23-4-ee-be-36, 8005, 0-23-4-ee-be-36, 8005,
0, 0), (8000, 0, 0), (8000,
8-17-f4-76-78-0, 5, 0, 8-17-f4-76-78-0, 5, 0,
0)] 0)]
Duplex 1 full full
Native Vlan 1 10 10
MTU 1 1500 1500
Admin port mode 1
Allowed VLANs - 10,20,30,40 10,20,30,40
vie# show vpc 5
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
vie#
The Flex System switch now includes one port channel that consists of four links to the Cisco
switches, instead of two port channels that consist of two links each to two N5000 switches,
as shown in Example 4-37 on page 154. The vPC 5 on Cisco does not need to be the same
vPC 5 that was used in the Flex System configuration. These values are significant only to
Cisco and the IBM Flex System switch.

Example 4-37 Output of show lacp command
Aggregator Id 5
----------------------------------------------
Individual - FALSE
Actor Oper Key - 5
Partner System ID - 00:23:04:ee:be:36
ready - TRUE
Min-Links - 1
index 0 port EXT24
index 1 port EXT21
index 2 port EXT22
index 3 port EXT23
MST spanning tree is still configured, as shown in Example 4-38. In contrast to the
configurations that do not include vPC, all four ports are in spanning tree status forwarding
because they all belong to the same LCAP channel.
Example 4-38 Output of show spanning-tree commands
------------------------------------------------------------------
------------------------------------------------------------------
VLANs MAPPED: 10 30
VLANs: 10 30
6000 00:05:9b:7b:84:3c 490 EXT21
61440 300 21
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f000-08:17:f4:76:78:00 8020 P2P
EXT21 (pc53) 128 490!+ FWD ROOT 6000-00:23:04:ee:be:36 9001 P2P
------------------------------------------------------------------
VLANs MAPPED: 20 40
VLANs: 20 40

6000 00:0d:ec:a3:8f:bc 1490 EXT21
61440 300 18
------------- ---- ---------- ----- ---- ---------------------- -------- ----------
EXT4 128 20000! FWD DESG f000-08:17:f4:76:78:00 8020 P2P
EXT24 (pc53) 128 str# show spanning-tree
No spanning tree instance exists.
str# show vpc peer-keep
--Last send at : 2012.05.23 19:40:51 754 ms
--Destination : 192.168.240.20
str# show vpc brief
Legend:
vPC domain id : 54
vPC role : primary
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------

------ ----------- ------ ----------- -------------------------- -----------
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
STP Mode 1 Rapid-PVST Rapid-PVST
STP Disabled 1 VLANs 1,10,20,30,40 VLANs 1,10,20,30,40
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
VLAN Mapping

Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
------------- ---- ---------------------- -----------------------
VLAN Mapping
Pass Vlans - 0-4095
Legend:
------------- ---- ---------------------- -----------------------
Shut Lan 1 No No
lag-id 1 [(7f9b, [(7f9b,
0-23-4-ee-be-36, 8005, 0-23-4-ee-be-36, 8005,
0, 0), (8000, 0, 0), (8000,
8-17-f4-76-78-0, 5, 0, 8-17-f4-76-78-0, 5, 0,
0)] 0)]
Duplex 1 full full
Native Vlan 1 10 10
MTU 1 1500 1500
Admin port mode 1
Allowed VLANs - 10,20,30,40 10,20,30,40
str# show vpc
Legend:
vPC domain id : 54
vPC role : primary

---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
str# show vpc peer-keep
--Last send at : 2012.05.23 19:40:51 754 ms
--Destination : 192.168.240.20
str# show vpc brief
Legend:
vPC domain id : 54
vPC role : primary
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------

1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)

VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
------------- ---- ---------------------- -----------------------
VLAN Mapping
Pass Vlans - 0-4095
Legend:
------------- ---- ---------------------- -----------------------
Shut Lan 1 No No
lag-id 1 [(7f9b, [(7f9b,
0-23-4-ee-be-36, 8005, 0-23-4-ee-be-36, 8005,
0, 0), (8000, 0, 0), (8000,
8-17-f4-76-78-0, 5, 0, 8-17-f4-76-78-0, 5, 0,
0)] 0)]
Duplex 1 full full
Native Vlan 1 10 10
MTU 1 1500 1500
Admin port mode 1
Allowed VLANs - 10,20,30,40 10,20,30,40
str# show vpc
Legend:
vPC domain id : 54

vPC role : primary
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
str# 490!+ FWD ROOT 8000-00:23:04:ee:be:36 9001 P2P

4.6 Use Case 5: LACP Channeling and vPC without spanning
tree
We can switch off spanning tree because we now have two switches that are connected with
one cable. The physical setup still consists of two Nexus 5000 switches and four 10 GE links,
as shown in Figure 4-12.
We disabled STP for VLANs 10, 20, 30, and 40.
After STP is switched off and LACP and vPC are used, the logical setup looks like two
switches that are connected by one cable. Because of this configuration, there is no need for
an STP to run to block redundant links, as shown in Figure 4-13 on page 163.
Use Case 5: Virtual Portchannel: Nexus 5K to IBM Flex System
EN2092 Ethernet Scalable Switch (physical view)
hostname:str
Nexus 5010
hostname:vie
Nexus 5020
hostname:Flex
PureFlex System
Eth 1/1 -2 Eth 1/1-2
Test-PC
Ext4
Ext21, Ext24
lacp key 5
Ext22, Ext23
lacp key 5
Eth 1/19-20 Eth 1/39-40
Po3
Po2
Po1
vpc peer-link
vPC5
mgnt0: 192.168.240.20/24
mgnt0: 192.168.240.30/24
vPC domain 54 vpc peer keep alive link
pc53 pc54

Figure 4-13 Use Case 5: Logical view
4.6.1 Configuring vPC on STR
The commands that are shown Example 4-39 were used to configure vPC on STR. The
Example 4-39 Use Case 5
str# show vpc peer-keepalive
--Last send at : 2012.05.23 19:40:51 754 ms
--Destination : 192.168.240.20
str# show vpc brief
Legend:
Use Case 5: Virtual Portchannel, no STP: Nexus 5K to
Flex System EN2092 Ethernet Scalable Switch (logical view)
Logical Switch
Nexus 5K(s)
Test-PC
Ext4
Ext21, Ext24
lacp key 5
Ext22, Ext23
lacp key 5
pc53
hostname:Flex
PureFlex System
logical view
PureFlex System

vPC domain id : 54
vPC role : primary
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
str# show vpc consistency-parameters int po1
Legend:

------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
------------- ---- ---------------------- -----------------------
VLAN Mapping
Pass Vlans - 0-4095
Legend:
------------- ---- ---------------------- -----------------------
Shut Lan 1 No No
lag-id 1 [(7f9b, [(7f9b,
0-23-4-ee-be-36, 8005, 0-23-4-ee-be-36, 8005,
0, 0), (8000, 0, 0), (8000,
8-17-f4-76-78-0, 5, 0, 8-17-f4-76-78-0, 5, 0,
0)] 0)]

Duplex 1 full full
Native Vlan 1 10 10
MTU 1 1500 1500
Admin port mode 1
Allowed VLANs - 10,20,30,40 10,20,30,40
str# show vpc
Legend:
vPC domain id : 54
vPC role : primary
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
str#
4.6.2 Configuring vPC on VIE
The commands that are shown Example 4-40 were used to configure vPC on the VIE switch.
Example 4-40 Use Case 5: vPC config VIE
vie# show vpc peer-keepalive
--Last send at : 2012.05.23 19:42:58 751 ms
--Destination : 192.168.240.30

vie# show vpc brief
Legend:
vPC domain id : 54
---------------------------------------------------------------------
-- ---- ------ --------------------------------------------------
1 Po1 up 1,10,20,30,40
vPC status
----------------------------------------------------------------------------
------ ----------- ------ ----------- -------------------------- -----------
vie# show vpc consistency-parameters global
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
VLAN Mapping

Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
vie# show vpc consistency-parameters int po 1
Legend:
------------- ---- ---------------------- -----------------------
QoS 2 ([], [3], [], [], [], ([], [3], [], [], [],
[]) [])
Network QoS (MTU) 2 (1538, 2240, 0, 0, 0, (1538, 2240, 0, 0, 0,
0) 0)
Priority)
Priority)
VLAN Mapping
Allowed VLANs - 1,10,20,30,40 1,10,20,30,40
vie# show vpc consistency-parameters vlan
------------- ---- ---------------------- -----------------------
VLAN Mapping
Pass Vlans - 0-4095
vie# show vpc consistency-parameters vpc 5
Legend:
------------- ---- ---------------------- -----------------------
Shut Lan 1 No No

lag-id 1 [(7f9b, [(7f9b,
0-23-4-ee-be-36, 8005, 0-23-4-ee-be-36, 8005,
0, 0), (8000, 0, 0), (8000,
8-17-f4-76-78-0, 5, 0, 8-17-f4-76-78-0, 5, 0,
0)] 0)]
Duplex 1 full full
Native Vlan 1 10 10
MTU 1 1500 1500
Admin port mode 1
Allowed VLANs - 10,20,30,40 10,20,30,40
4.6.3 Disabling STP on the Flex System switch
The commands that are shown Example 4-41 were used to disable STP on the Flex System
switch. The important parameters and details are highlighted in red.
Example 4-41 Use Case 5: Flex System switch
!
!
!
Show spanning tree on Flex
------------------------------------------------------------------
------------------------------------------------------------------
------------------------------------------------------------------
MSTP is not on.

Chapter 5. Cisco Catalyst 6500 switch
connectivity
Many customers still use the Cisco Catalyst 6500 switch in their data center. This chapter
describes the use case that we performed with the IBM Flex System chassis and the Catalyst
6500 switch.
5

5.1 Use Case 1: LACP channeling and vPC without spanning
tree
We had only one Catalyst 6500 switch available for this use case. We connected the one Flex
System switch to one Catalyst 6500 switch by using four parallel links, as shown in Figure 5-1.
Figure 5-1 Catalyst 6500 Use Case
5.1.1 Catalyst 6500 switch configuration
The Catalyst 6500 switch configuration that was used in this use case is shown in
Example 5-1. The important parameters and details are highlighted in red.
Example 5-1 Catalyst 6500 switch configuration
lldp run
interface Port-channel100
switchport
switchport trunk encapsulation dot1q
!
...
interface TenGigabitEthernet3/1
description TO_Flex_EXT21
switchport
Cisco Catalyst 6500 to IBM Flex System EN2092
Ethernet Scalable Switch
hostname:C65K
Catalyst 6500
Test-PC
Ext4
Ext21, Ext24
lacp key 121
Ext22, Ext23
lacp key 121
hostname:Flex
PureFlex System
TenGI 3/1-4
Po100

Chapter 5. Cisco Catalyst 6500 switch connectivity 173
!
switchport
!
switchport
!
switchport
C6K#sh lldp neighbors
Capability codes:
Flex Te3/1 120 B,R 49
Flex Te3/4 120 B,R 52
Flex Te3/3 120 B,R 51
Flex Te3/2 120 B,R 50
Total entries displayed: 4Te3/2 120 B,R 50

5.1.2 Flex System switch configuration
The Flex System switch configuration that was used in this use case is shown in Example 5-2.
Example 5-2 Flex System switch configuration
!
!
!
name "TO_C6K_TEN3/1"
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
tagging
pvid 10
exit
!
…
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
lacp mode active
lacp key 121
!
lacp mode active

Chapter 5. Cisco Catalyst 6500 switch connectivity 175
lacp key 121
!
!
----------|-------|---------------------------|----------------------|-------------------
EXT21 | 6 | 00 1a 2f 00 a0 d6 | TO_Flex_EXT21 | C6K.cisco.com
Flex#sh lacp aggregator
Aggregator Id 49
----------------------------------------------
Individual - FALSE
Partner System ID - 00:19:07:a9:07:00
ready - TRUE
Min-Links - 1
index 0 port EXT21
index 1 port EXT22
index 2 port EXT23
index 3 port EXT24
Flex#sh int status
------------------------------------------------------------------
------- ---- ----- -------- --TX-----RX-- ------ ------
…
EXT21 49 10000 full no no up TO_C6K_TEN3/1
---------------------------------------------------------------------------------
…
EXT21 active 121 121 yes 32768 49 53 up 1
EXT22 active 121 121 yes 32768 49 53 up 1
EXT23 active 121 121 yes 32768 49 53 up 1
EXT24 active 121 121 yes 32768 49 53 up 1
Flex#sh lacp aggregator

Aggregator Id 49
----------------------------------------------
Individual - FALSE
Partner System ID - 00:19:07:a9:07:00
ready - TRUE
Min-Links - 1
index 0 port EXT21
index 1 port EXT22
index 2 port EXT23
index 3 port EXT24

Appendix A. Troubleshooting
The methodology and commands that are used for troubleshooting connectivity problems are
described in this appendix. A sample of network documentation also is provided.
In this Redpaper, the focus thus far has been placed on Layer 2. Therefore, the focus of this
appendix is on problems about Ethernet, VLANs, and spanning tree.
In the first part, we describe a useful troubleshooting methodology. In the second part, you
find the most common commands to show and verify the status of the configuration, which
help you to track down the root cause of your problem. The last part of the appendix shows a
sample of network documentation, which is the information you need with which to
troubleshoot.
This appendix includes the following topics:
򐂰 Basic troubleshooting for connectivity problems
򐂰 Baseline documentation
򐂰 Firmware update of IBM Flex System network switches
A
Nexus 5000 switch upgrades: For more information about how to upgrade NX-OS for the
Nexus 5000 Series switches, see this website:
http://www.cisco.com/en/US/products/ps9670/products_configuration_example09186a
0080b4b9dd.shtml

Basic troubleshooting for connectivity problems
This section describes basic troubleshooting techniques.
Approach
This basic Layer 2 troubleshooting guideline supports you when you are looking for
connectivity problems of adjacent devices. These devices are devices that should be able to
communicate with each other on Layer 2. This configuration might be two hosts in the same
VLAN or a host and its default gateway.
The following symptoms often indicate a problem:
򐂰 Failing application or failing pings between adjacent devices.
򐂰 Address resolution protocol (ARP) failures (missing or “incomplete” ARP entry).
򐂰 Missing packets on the receiving host that are shown with a packet sniffer.
Verify connectivity
Before you are start troubleshooting on Layer 2, you should verify the following connectivity
configurations on Layer 3:
򐂰 Ping the two devices from each other. Do you receive an Internet Control Message
Protocol (ICMP) echo in one or other direction?
If you do not receive an echo, the following causes for a ping failure are possible:
– A Firewall or personal firewall on a host
– Wrong or missing default gateway (DGW)
– Wrong IP subnet mask
򐂰 Verify that the ARP caches on the devices. Even if a ping does not work, it is possible that
the address resolution protocol (ARP) did work. This status indicates a working Layer 2
link and a problem on the IP level (Layer 3). Even if the ping fails, the ARP entries should
be verified.
Determine the Layer 2 path
When you are at the point that your problem seems to be a Layer 2 or Layer 1 problem, you
want to reduce the scope of the potential failures. This common troubleshooting method
might help you to diagnose your problem.
In the first step, it is useful to determine the expected Layer 2 path that is based on
documentation, baselines, and general knowledge of the network. Determining the Layer 2
path shows the path that the traffic is expected to take between the two affected hosts. The
analysis results indicate a good starting point for the next steps of gathering information about
what is happening in the network, and make it easier to detect abnormal behavior.
Track the traffic flow across the Layer 2 path
The second step is to follow the expected path and verify that the links are up and forwarding
traffic. If the actual path is different from the expected path, this conflict can indicate where to
proceed with troubleshooting, what links and protocols are involved, and might cause the
failure. Often included in this process is comparing the spanning tree topology against the
expected Layer 2 topology. If the actual topology differs from the expected, this difference
might give some clue about the cause of the problem.
Verification of traffic flows can be done by showing MAC address tables, interface statistics,
and so on.

Appendix A. Troubleshooting 179
Analyze links
After you find a divergence between the expected and the current traffic path, you should
examine the links to determine where the expected path is broken. You can start to target
troubleshooting commands to narrow down the root cause of the problem. Even if you cannot
figure out on yourself the root cause, you can establish a good base of information and
documentation for problem escalation.
Figure A-1 shows an overview of the troubleshooting steps.
Figure A-1 Troubleshooting flowchart
Layer 2 troubleshooting commands
The following commands are listed according to the workflow that we described in the
previous section.
Verify connectivity
Verify the connectivity by using the following ping:
ping 10.1.1.1
Connection testing (ping).
ARP caches check.
Determine expected Layer 2 path with
documentation and baselines.
Verify operational Layer 2 path with LLDP
and port status verification.
Verify Spanning Tree Protocol status and
forwarding links.
Analyze MAC address tables.
Analyze counters and traffic statistics.
Analyze captured packets.
VLAN: analyze and verify existence and
forwarding.
Port: analyze and verify access and
tagged port operation and PVID.
Trunk: analyze and verify trunk link
operation.
Track device MAC
addresses and frames
along L2 path
Analyze links where
paths seem broken
Determination and
verification of layer 2
path
Layer 3 connectivity
between adjacent
devices?
START

Verify the ARP cache
When you start a ping, the host needs to know the destination MAC address first so it can
address the Ethernet frame properly. To determine the destination MAC address, the host
sends an ARP request frame, which is responded to with an ARP reply. The ARP reply
contains the destination IP and MAC address. This information is stored in the ARP cache,
often for a few minutes.
If the ping failed and you can find the destination MAC address in the ARP cache, this result is
a strong indication that your Layer 2 connectivity is working. You might experience problems
with a firewall or other security measures on a device.
Use the following commands to display the ARP cache:
򐂰 On a Windows host: arp –a
򐂰 On the switch: show ip arp
Determination of Layer 2 path
You use the existing network documentation and compare the current network condition
against it. If the documentation is missing, you document the current network situation by
using the following command results as input:
򐂰 Use the following commands to verify which interfaces are up, duplex, speed, and so on:
– IBM: show interface link
– Cisco: show interfaces status
򐂰 Use the following commands to verify the mapping of ports and VLANs:
– IBM: show interface information
– Cisco: show interface trunk
򐂰 Use the following commands to verify the interconnection of switches and routers:
– IBM: show lldp remote-device
– Cisco: show lldp neighbors
򐂰 Use the following commands to verify the forwarding of traffic on links:
– IBM and Cisco: show spanning-tree
– IBM and Cisco: show interface counters
򐂰 Use the following commands to verify the LACP trunks:
– IBM: show portchannel information
– Cisco: show etherchannel summary
Tracking traffic along L2 path
After you know what your actual network looks like, you can track the flow of traffic across it.
This tracking is best done by tracking MAC addresses. Every switch holds a table of MAC
addresses. The table is built and updated with every new Ethernet frame that crosses the
switch by putting the source MAC address and the switchport ID where the frame entered the
switch into the MAC address table. This information is needed by the switch when an Ethernet
frame is forwarded to the specific MAC address. Any destination MAC address can be
mapped to a switchport.
If a frame is to be forwarded but there is no valid entry in the MAC address table, the frame is
broadcasted on all ports, except the port where the frame entered the switch. There are
instances in which this configuration makes sense to clear the table, initiate some traffic, and
verify it again.

Reviewing this table shows you where the switch sees the device with that specific MAC
address connected.
Use the following commands to show the current content of the table:
򐂰 IBM: show mac-address-table
򐂰 Cisco: show mac address-table
Use the following commands to clear the current content of the table:
򐂰 IBM: clear mac-address-table
򐂰 Cisco: clear mac address-table
Analyze links where path seems broken
When you find a path that seems to be broken, the following commands can help to analyze
the root cause of the problem:
򐂰 Use the following commands to verify the existence and the correct forwarding of the
VLANs:
– IBM and Cisco: show vlan
– Cisco: show interface switchport
– IBM and Cisco: show spanning-tree
򐂰 Use the following commands to verify the correct membership and tagging on the switch
ports and interswitch links:
– Cisco: show interface trunk
– Cisco: show interface status
Baseline documentation
Experience shows that documenting a network is a difficult task. Often there is too much or
not enough information, or the information is not what you need.
To simplify the effort of creating and reading the documentation of a network, it might make
sense to separate the documentation by OSI Layers 1, 2 and 3. Each of these layers is
reflected by its own configuration in the network devices. You also can troubleshoot the layers
individually. The following drawings shall show a simple network:
Figure A-2 on page 182 shows the cabling, devices, naming convention that is used, and
ports of OSI Layer 1.

Figure A-2 OSI Layer 1
Figure A-3 shows the VLANs, ports, VLAN membership, tagging, and PVID of OSI Layer 2.
Figure A-4 shows the IP subnets, routes, and default gateway of OSI Layer 3.
PC 1
10.10.0.10/24
Port 18
1 Gb
Serial
console
IBM G8264
Port 63
Port 64
Te 1/0/1
Te 1/0/2
LACP 802.1ad
Cisco 2960S-48
PC 2
10.30.0.10/24
GI 1/0/1
1 Gb
2 x 10 Gb
Cisco 2960S
IBM G8264
PC 1
10.10.0.10/24
VLAN 10
Port 17
VLAN 1
VLAN 10
VLAN 20
VLAN 30
Inline-
management
PC 2
10.30.0.10/24
GI 1/0/1
VLAN 30
VLAN 10
"Management"
10.10.0.0/24
VLAN 30
"Client"
10.30.0.0/24
VLAN 20
"Server"
10.20.0.0/24
Default Gateway DGW
.1 .1
.1

Additional useful information for baseline documentation
The following useful information also is used in baseline documentation:
򐂰 Average and peak bandwidth for switch-to-switch links and switch-to-server links.
򐂰 Average rate of broadcasts and multicasts in the network.
򐂰 Software version that is used and the date of last firmware update.
Firmware update of IBM Flex System network switches
The Ethernet switch firmware can be updated by using one of the following methods:
򐂰 The use of a graphical user interface (GUI)
򐂰 Through Flex System Manager (FSM) by using the Update Manager
򐂰 The use of the Command-line Interface (CLI)
If there an FSM module is not installed, you can use one of the following ways to update the
firmware of the integrated network switches.
For more information, see the IBM Flex System Information Center at this website:
http://publib.boulder.ibm.com/infocenter/flexsys/information/topic/com.ibm.acc.net
workdevices.doc/network_iomodule.html
Update the switch by using the web-based GUI
Complete the following steps to update the switch by using the browser-based GUI:
1. Go to the IBM Fix Central website: http://ibm.com/support/fixcentral/options
2. Select the choices as shown in Figure A-5 on page 184 and click Continue.

Figure A-5 Fix Central window
3. Select the products that you want to install and click Continue, as shown in Figure A-6.
Figure A-6 Selecting fixes
4. Log in by using your IBM ID and select your preferred download, as shown in Figure A-7
on page 185.

Figure A-7 Download options
5. Accept the terms and conditions.
6. Download the Firmware package.
7. Check the readme file for updates of the update process.
8. Extract the boot and OS image files into a directory.
The compressed file that contains the following files and directories:
– Boot image: ibm_fw_scsw_en2092-7.2.2.2_anyos_noarch_Boot.img
– OS image: ibm_fw_scsw_en2092-7.2.2.2_anyos_noarch_OS.img
– A directory that contains the MIB files
9. Establish a connection between the Ethernet port of the Chassis Management Module
(CMM) and the machine that is running the browser.
For more information about how to configure an IP address on a Switch module, see the
CMM documentation.
10.Enter the IP address of the Switch and log in to the browser-based user interface (BBI) by
using the following credentials:
– Username (default): admin (or USERID)
– Password (default): admin (or PASSW0RD)
11.Click the Configure tab, as shown in Figure A-8 on page 186.
12.From the left-tree view, click IBM Flex System EN2092 10 Gb Switch  System 
Config/Image Control.
13.Scroll down to the Image Settings group, as shown in Figure A-8 on page 186, and
complete the following steps:
a. In the Image for Transfer menu, select the wanted OS image bank.
b. Click Browse and browse to your local file system to select the OS image file:
ibm_fw_scsw_en2092-7.x.x.x_anyos_noarch_OS.img.
c. Click Download via Browser.

Figure A-8 Updating the firmware
The file transfer begins, followed by flashing non-volatile memory on the Switch. When the
operation completes, the browser window returns and you see the following message at
the bottom of the page:
Status of Previous Transfer ...
... Image downloaded via Browser ibm_fw_scsw_en2092-7.x.x.x_anyos_noarch_OS.img
- Successful
***If you want to update both image banks, repeat step e above for the second
image bank before updating the boot image below.
14.Repeat step 13 on page 185 and select the boot image from the menu and select the
ibm_fw_scsw_en2092-7.x.x.x_anyos_noarch_Boot.img file.
The file transfer begins, followed by flashing non-volatile memory on the Switch. When the
operation completes, the browser window returns and you see the following message at
the bottom of the page:
Status of Previous Transfer …
... Image downloaded via Browser ibm_fw_scsw_en2092-7.x.x.x_anyos_noarch
_Boot.img - Successful
15.Set the Next Boot Image Selection to the image bank (1 or 2) that contains the new
firmware, as shown in Figure A-9 on page 187.
16.Click Submit at the bottom of the page.
17.Click REBOOT! at the bottom of the page.
18.Wait for the switch to reboot.
Do not reset: Do not reset or boot the switch between the OS and boot upgrades.

Figure A-9 Completing the firmware update
Using SSHv2 or Telnet
This method uses a Trivial File Transfer Protocol (TFTP) or File Transfer Protocol (FTP) server
to update the switch firmware. Often, this server is installed on a machine that is reachable
from the switch through the management module. However, when the switch is appropriately
configured, the server can be attached to the external management port or an external or
internal data port.
Complete the following steps to use SSHv2 or Telnet:
1. Download the compressed VFSS software package file to the machine where the TFTP
(or FTP) server is located.
2. Extract the boot and OS image files into a directory. Enable the server and set its default
directory to the one in which the image files is located.
3. Establish a connection between the Ethernet port of the Management Module and the
TFTP Server. For more information about configuring an IP address on a Switch module,
see the CMM documentation.
4. Open a session by using the IP address of the Switch and log in to the VFSS Command
Line Interface (CLI) by using the following credentials:
– Username (default): admin (or USERID)
– Password (default): admin (or PASSW0RD)
Important: Telnet is disabled by default. Unless you previously enabled telnet, use SSHv2.

5. Upgrade the OS image by entering the following command:
/boot/gtimg X TADDR Ibm_fw_scsw_en2092-7.x.x.x_anyos_noarch_OS.img
Where:
– X = 1 or 2 (determined by the image bank you want to use)
– TADDR = IP address of the TFTP Server
It is recommended that you retain the previous OS version by loading the upgrade into the
other image block and then reset the switch by using the new image. Use the /boot/image
command to select the preferred image. Leave the user name blank for TFTP (press Enter
and answer “Y” to the confirmation question). Wait for the upgrade to complete
successfully.
6. Upgrade the boot image by entering the following command:
/boot/gtimg boot TADDR Ibm_fw_scsw_en2092-7.x.x.x_anyos_noarch_Boot.img
Leave the user name blank for TFTP (press Enter and answer 'Y' to the confirmation
question). Wait for the upgrade to complete successfully.
7. After the boot upgrade completes, reset the switch by using the following command:
/boot/reset
You must reset the switch to activate the new image.
When you reset the switch, it boots by using the selected image (1 or 2). Ensure that you
are booting from the upgraded image by running the /boot/cur command.
A switch reset completes in approximately 60 seconds.
8. After rebooting, you can verify the firmware version by using the show version command,
as shown in Example A-1 on page 189.
Important: Do not reset the switch between the OS and boot upgrades.

Example: A-1 Verifying the firmware version
Router>show version
System Information at 23:48:16 Mon May 21, 2012
Time zone: America/US/Pacific
Daylight Savings Time Status: Disabled
IBM Flex System EN2092 1Gb Ethernet Scalable Switch
Switch has been up for 0 days, 0 hours, 4 minutes and 9 seconds.
Last boot: 23:46:05 Mon May 21, 2012 (reset from Telnet/SSH)
MAC address: 08:17:f4:76:78:00 IP (If 1) address: 0.0.0.0
Management Port MAC Address: 08:17:f4:76:78:ef
Management Port IP Address (if 128): 192.168.10.201
Software Version 7.2.2.2 (FLASH image1), active configuration.
Hardware Part Number : 49Y4295
Hardware Revision : 00
Serial Number : Y050VT16E0AK
Manufacturing Date (WWYY) : 3711
PCBA Part Number : BAC-00079-00
PCBA Revision : 0
PCBA Number : 00
Board Revision : 00
PLD Firmware Version : 1.3
Temperature Warning : 36 C (Warn at 60 C/Recover at 55 C)
Temperature Shutdown : 36 C (Shutdown at 65 C/Recover at 60 C)
Temperature Inlet : 33 C
Temperature Exhaust : 36 C
Temperature Local : 35 C
Temperature Remote 1 : 54 C
Temperature Phy 0x01 : 54 C
Power Consumption : 37.980 W (12.408 V, 3.061 A)
Switch is in I/O Module Bay 1
Router>

ARP Address Resolution Protocol
BBI browser-based interface
BPDU Bridge protocol data unit
CDP Cisco Discovery Protocol
CLI command-line interface
CMM Chassis Management Module
DA destination address
DGW default gateway
DOCSIS Data Over Cable Service Interface
Specification
FDB forwarding database
FSM Flex System Manager
FTP File Transfer Protocol
GE Gigabit Ethernet
GUI graphical user interface
ICMP Internet control message protocol
ID identifier
IEEE Institute of Electrical and
Electronics Engineers
IGMP Internet Group Management
Protocol
IP Internet Protocol
ISCLI industry standard command line
interface
ISL Inter-Switch Link
ITSO International Technical Support
Organization
LACP Link Aggregation Control Protocol
LACPDU LACP Data Units
LAG link aggregate group
LAN local area network
LCAP Link Aggregation Control Protocol
LLDP Link Layer Discovery Protocol
MAC media access control
MEC Multichassis Ether Channel
MIB management information base
MLT Master Latency Timer
MST Multiple Spanning Tree
MSTP Multiple Spanning Tree Protocol
MTU maximum transmission unit
OS operating system
OSI Open Systems Interconnect
Abbreviations and acronyms
OUI organizationally unique identifier
PC personal computer
PDU power distribution unit
PVRST Per VLAN Rapid Spanning Tree
PVST Per-VLAN Spanning Tree
RMON Remote Monitoring
RSS Receive-side scaling
RSTP Rapid Spanning Tree Protocol
SA source address
STP Spanning Tree Protocol
TCA Target Channel Adapter
TCN Topology Change Notification
TFTP Trivial File Transfer Protocol
TTL time to live
VLAG Virtual Link Aggregation Groups
VLAN virtual LAN

Related publications
The publications that are listed in this section are considered particularly suitable for a more
detailed discussion of the topics that are covered in this paper.
IBM Redbooks
The following IBM Redbooks publications provide additional information about the topics in
this document. Note that some publications referenced in this list might be available in
softcopy only:
򐂰 Implementation of IBM j-type Ethernet Switches and Routers, SG24-7882
򐂰 IBM Flex System Networking in an Enterprise Data Center, REDP-4834
򐂰 IBM PureFlex System and IBM Flex System Products and Technology, SG24-7984
򐂰 IBM Flex System EN2092 1Gb Ethernet Scalable Switch, TIPS0861
򐂰 IBM Flex System Fabric EN4093 10Gb Scalable Switch, TIPS0864
You can search for, view, download, or order these documents and other Redbooks,
Redpapers, Web Docs, draft, and additional materials at the following website:
http://www.ibm.com/redbooks
Other publications
The following publications are also relevant as further information sources:
򐂰 IBM RackSwitch G8264 Application Guide (6.8):
http://ibm.com/support/docview.wss?uid=isg3T7000464
򐂰 Virtual PortChannel Quick Configuration Guide:
http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/configuration
_guide_c07-543563.html
򐂰 Cisco Nexus 5000 Series NX-OS Software Configuration Guide, Configuring Multiple
Spanning Tree:
http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/configuration/
guide/cli_rel_4_0_1a/MST.html

Online resources
The following websites are also relevant as further information sources:
򐂰 ProCurve & Cisco Spanning Tree Interoperability
http://cdn.procurve.com/training/Manuals/ProCurve-and-Cisco-STP-Interoperabilit
y.pdf
򐂰 Best Practice for configuring HP procurve with Cisco switch forum
http://h30499.www3.hp.com/t5/Switches-Hubs-Modems-Legacy-ITRC/Best-Practice-for
-configuring-HP-procurve-with-Cisco-switch/td-p/4701340
򐂰 Radia Perlman, Intel Labs, Donald Eastlake, Huawei Technologies, Introduction to Trill,
The Internet Protocol Journal, Volume 14, No. 3:
http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_14-3/143_trill.h
tml
Help from IBM
IBM Support and downloads
ibm.com/support
IBM Global Services
ibm.com/services

®
REDP-4901-00
INTERNATIONAL
TECHNICAL
SUPPORT
ORGANIZATION
BUILDING TECHNICAL
INFORMATION BASED ON
PRACTICAL EXPERIENCE
IBM Redbooks are developed
by the IBM International
Technical Support
Organization. Experts from
IBM, Customers and Partners
from around the world create
timely technical information
based on realistic scenarios.
Specific recommendations
are provided to help you
implement IT solutions more
effectively in your
environment.
For more information:
ibm.com/redbooks
Redpaper™
Deploying IBM Flex System
into a Cisco Network
Learn how to
integrate IBM Flex
System into your
network
See real life Layer 2
configurations with
Flex System switches
Find out how easy it is
to connect network
devices
This IBM Redpaper publication provides information on how to integrate
IBM Flex System into an existing customer network. It focuses on
interoperability and seamless integration from the network perspective.
The paper describes the complete configuration of the most common
scenarios. It guides you through several setups, and shows in detail
how to configure the network switches, and how to verify the
functionality and proper operation.
This paper can help you to easily configure and monitor your Layer 2
setup. Typical well established Layer 2 Network setups use
combinations of Spanning Tree Protocol, VLANs and link aggregation.
Scenarios described in this paper includes the use of these switching
products:
򐂰 Cisco Nexus 5000 (including vPC)
򐂰 Cisco Catalyst 6500
򐂰 IBM RackSwitch (including VLAG)
򐂰 IBM Flex System Ethernet Scalable Switch (including VLAG)
We describe the use of these switches with each of the following
Spanning Tree Protocol (STP) configurations:
򐂰 RSTP (Rapid STP)
򐂰 MSTP (Multiple STP)
򐂰 PVRST (Per VLAN Rapid STP)
򐂰 STP disabled
The paper is aimed at network administrators familiar with Cisco
network products. It uses the industry standard command-line
interface (isCLI) as management interface and we assume the reader
is familiar with Cisco products and the use of isCLI.
Back cover

Deploying IBM Flex System into a Cisco Network

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