SlideShare a Scribd company logo
CCNA Guide to Cisco Networking Fundamentals  Chapter 12 Basic Switching and Switch Configuration
Objectives Explain the technology and media access control method for Ethernet networks Explain network segmentation and basic traffic management concepts Explain basic switching concepts and the operation of Cisco switches Perform and verify switch configuration tasks Implement basic switch security CCNA Guide to Cisco Networking Fundamentals
Ethernet Operations Ethernet A  network access method  (or  media access method ) originated by the University of Hawaii, later adopted by Xerox Corporation And standardized as IEEE 802.3 in the early 1980s Ethernet is: Most pervasive network access method in use Most commonly implemented media access method in new LANs CCNA Guide to Cisco Networking Fundamentals
CSMA/CD Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Ethernet contention method Any station connected to a network can transmit anytime a transmission is not present on the wire Interframe gap , or  interpacket gap (IPG) After each transmitted signal, each station must wait a minimum of 9.6 microseconds before transmitting another packet CCNA Guide to Cisco Networking Fundamentals
CSMA/CD (continued) Collisions Two  stations could listen to the wire simultaneously and not sense a  carrier signal Both stations might begin to transmit their data simultaneously Once a collision is detected, the first station to detect the collision transmits a 32-bit  jam signal Tells all other stations not to transmit for a brief period The two stations that caused the collision use an algorithm to enter a  backoff period CCNA Guide to Cisco Networking Fundamentals
CSMA/CD (continued) Collision domain The physical area in which a packet collision  might occur Routers, switches, bridges,  and gateways segment networks And thus create separate collision domains The 32-bit jam signal that is transmitted when the collision is discovered prevents all stations on that collision domain from transmitting CCNA Guide to Cisco Networking Fundamentals
CSMA/CD (continued) Broadcasts Stations on a network broadcast packets to other stations to make their presence known on the network  And to carry out normal network tasks When a segment has too much broadcast traffic: Utilization increases Network performance in general suffers Simple ways to reduce broadcast traffic: Reduce the number of services on your network Limit the number of protocols in use on your network CCNA Guide to Cisco Networking Fundamentals
CSMA/CD (continued) Broadcast storm A sudden rush of network transmissions that causes all other network communications to slow down Due to the volume of data competing for access to the same bandwidth on the  communications medium One of the most common causes of broadcast storms is a network  loop CCNA Guide to Cisco Networking Fundamentals
Latency Latency , or  propagation delay The length of time that is required to forward, send, or otherwise propagate a data frame Latency differs depending on the resistance offered by the transmission medium, the number of nodes  And in the case of a connectivity device, the amount of processing that must be done on the packet Transmission time The amount of time it takes for a packet to be sent from one device to another CCNA Guide to Cisco Networking Fundamentals
Latency (continued) CCNA Guide to Cisco Networking Fundamentals
Latency (continued) Bit time Refers to the amount of time required to transmit one data bit on a network Slot time  (512 bit times) An important specification that limits the physical size of each  Ethernet collision domain Specifies that all collisions should be detected from anywhere in a network in less time than is required to place a 64-byte frame on the network CCNA Guide to Cisco Networking Fundamentals
Ethernet Errors Frame size errors Short frame or runt Long frame or giant Jabber Frame check sequence (FCS) error Indicates that bits of a frame were corrupted during transmission Can be caused by any of the previously listed errors CCNA Guide to Cisco Networking Fundamentals
Ethernet Errors  (continued) Collision errors Reducing the number of devices per collision domain will usually solve the problem You can do this by segmenting your network with a router, a bridge, or a switch Late collision Occurs when two stations transmit more than 64 bytes of data frames before detecting  a collision CCNA Guide to Cisco Networking Fundamentals
Ethernet Errors  (continued) Fast Ethernet Uses the same CSMA/CD as common 10BaseT Ethernet Provides ten times the data transmission rate—100 Mbps Defined under the  IEEE 802.3u  standard Implementations 100Base-TX 100Base-T4 100Base-FX CCNA Guide to Cisco Networking Fundamentals
Gigabit Ethernet Recent advances in technology have allowed us to reach even higher speeds than those of Fast Ethernet Gigabit Ethernet implementations 1000Base-TX (802.3ab) 1000Base-SX (802.3z) 1000Base-LX (802.3z) 1000Base-CX (802.3z) CCNA Guide to Cisco Networking Fundamentals
Half- and Full-Duplex Communications Half-duplex  communications Devices can send and receive signals, but not at the same time Full-duplex  (or  duplex ) communications Devices can send and receive signals simultaneously Ethernet networks can use equipment that supports half- and full-duplex communications CCNA Guide to Cisco Networking Fundamentals
CCNA Guide to Cisco Networking Fundamentals
Half- and Full-Duplex Communications (continued) Benefits of using full-duplex: Time is not wasted retransmitting frames because collisions do not occur The full bandwidth is available in both directions because the send and receive functions are separate Stations do not have to wait until other stations complete their transmissions because only one transmitter is used for each twisted pair CCNA Guide to Cisco Networking Fundamentals
Half- and Full-Duplex Communications (continued) On a Cisco Catalyst 2950 switch, you can set the duplex capabilities port-by-port The four different duplex options are: Auto Full Full-flow control Half CCNA Guide to Cisco Networking Fundamentals
A Review of LAN Segmentation You can improve the performance of your Ethernet network By reducing the number of stations per collision domain Typically, network administrators implement bridges, switches, or routers to segment the network and divide the collision domains CCNA Guide to Cisco Networking Fundamentals
Segmenting with Bridges Bridge Segments a network by filtering traffic at the Data Link layer Divides a network into two or more segments Only forwards a frame from one segment to another if the frame is a broadcast or has the MAC address of a station on a different segment Bridges learn MAC addresses by reading the source MAC addresses from frames As the frames are passed across the bridge CCNA Guide to Cisco Networking Fundamentals
Segmenting with Bridges (continued) Bridging table Maps the MAC addresses on each segment to the corresponding port on the bridge to which each segment is connected Bridges increase latency, but because they effectively divide the collision domain This does not affect slot time CCNA Guide to Cisco Networking Fundamentals
Segmenting with Bridges (continued) Remember these points: Bridges reduce collisions on the LAN and filter traffic based on MAC addresses A bridge does not reduce broadcast or  multicast  traffic A bridge can extend the useful distance of the Ethernet LAN The bandwidth for the new individual segments is increased Bridges can be used to limit traffic for security purposes CCNA Guide to Cisco Networking Fundamentals
Segmenting with Routers Router Operates at layer 3 of the OSI reference model Interprets the Network layer protocol and makes forwarding decisions based on the layer 3 address Routers typically do not propagate broadcast traffic Thus, they reduce network traffic even more than bridges do Routers maintain routing tables that include the Network layer addresses of different segments CCNA Guide to Cisco Networking Fundamentals
Segmenting with Routers (continued) When you segment a LAN with routers, they will: Decrease collisions by filtering traffic Reduce broadcast and multicast traffic by blocking or selectively filtering packets Support multiple paths and routes between them Provide increased bandwidth for the newly created segments Increase security by preventing packets between hosts on one side of the router from propagating to the other side of the router CCNA Guide to Cisco Networking Fundamentals
Segmenting with Routers (continued) When you segment a LAN with routers, they will: (continued) Increase the effective distance of the network by creating new collision domains Provide layer 3 routing, packet fragmentation and reassembly, and traffic flow control Provide communications between different technologies, such as Ethernet and Token Ring or Ethernet and Frame Relay Have a higher latency than bridges, because routers have more to process; faster processors in the router can reduce some of this latency CCNA Guide to Cisco Networking Fundamentals
LAN Switching Switches Similar to bridges in several ways Using a switch on a LAN has a different effect on the way network traffic is propagated CCNA Guide to Cisco Networking Fundamentals
Segmentation with Switches Switches are often called  multiport bridges Switch typically connects multiple stations individually Thereby segmenting a LAN into multiple collision domains Switches  microsegment  the network By connecting each port to an individual workstation Switched bandwidth Bandwidth is not shared as long as each workstation connects to its own switch port CCNA Guide to Cisco Networking Fundamentals
Segmentation with Switches (continued) CCNA Guide to Cisco Networking Fundamentals
CCNA Guide to Cisco Networking Fundamentals
Segmentation with Switches (continued) Switch latency is typically higher than that of a repeater or hub Faster processors and a variety of switching techniques make switches typically faster than bridges Switches provide the following benefits: Reduction in network traffic and collisions Increase in available bandwidth per station Increase in the effective distance of a LAN by dividing it into multiple collision domains Increased security, because unicast traffic is sent directly to its destination CCNA Guide to Cisco Networking Fundamentals
Switch Operations A switch learns the hardware address of devices to which it is attached By reading the source address of frames as they are transmitted across the switch The switch then matches the source MAC address with the port from which the frame was sent The MAC-to-switch-port mapping is stored in the switch’s  content-addressable memory (CAM) The switch uses a memory buffer to store frames as it determines to which port(s) a frame will be forwarded CCNA Guide to Cisco Networking Fundamentals
Switch Operations (continued) Types of memory buffering:  Port-based memory buffering Shared memory buffering Asymmetric switching Some switches can interconnect network interfaces of different speeds Symmetric switching Switches that require all attached network interface devices to use the same transmit/receive speed CCNA Guide to Cisco Networking Fundamentals
Switching Methods All switches base frame-forwarding decisions on a frame’s destination MAC address The three main methods for processing and forwarding frames are: Cut-through, store-and-forward, and fragment-free One additional forwarding method, adaptive cut-through forwarding A combination of the cut-through and store-and-forward methods CCNA Guide to Cisco Networking Fundamentals
Switching Methods (continued) CCNA Guide to Cisco Networking Fundamentals
Cut-Through Forwarding Switches that use  cut-through forwarding  start sending a frame immediately after reading the destination MAC address into their buffers The main benefit of cut-through forwarding is a reduction in latency The drawback is the potential for errors in the frame that the switch would be unable to detect Because the switch only reads a small portion of the frame into its buffer CCNA Guide to Cisco Networking Fundamentals
Cut-Through Forwarding (continued) CCNA Guide to Cisco Networking Fundamentals
Store-and-Forward Forwarding Store-and-forward  switches read the entire frame, no matter how large, into their buffers before forwarding Because the switch reads the entire frame, it will not forward frames with errors The store-and-forward method has the highest latency CCNA Guide to Cisco Networking Fundamentals
Store-and-Forward Forwarding (continued) CCNA Guide to Cisco Networking Fundamentals
Fragment-Free Forwarding Fragment-free forwarding  represents an effort to provide more error-reducing benefits than cut-through switching While keeping latency lower than does store-and-forward switching A fragment-free switch reads the first 64 bytes of an Ethernet frame And then begins forwarding it to the appropriate port(s) CCNA Guide to Cisco Networking Fundamentals
Fragment-Free Forwarding (continued) CCNA Guide to Cisco Networking Fundamentals
Fragment-Free Forwarding (continued) Adaptive cut-through For the most part, the adaptive cut-through switch will act as a cut-through switch To provide the lowest latency However, if a certain level of errors is detected, the switch will: Change forwarding techniques Act more as a store-and-forward switch CCNA Guide to Cisco Networking Fundamentals
Switch User Interface Two types of operating systems are in use on Cisco switches: IOS-based and set-based You can connect to a Cisco switch in the same way you connect to a Cisco router The Cisco switch has a console port to which you can connect your laptop or PC Once you power on the switch you will be in the command-line interface You can configure anything from the command line CCNA Guide to Cisco Networking Fundamentals
Modes and Passwords You cannot actually configure a switch until you get to enable mode To enter enable mode, type  enable  at the command-line prompt and then press Enter The first step in configuring a switch is to set up a password To start configuration mode, first type  configure terminal  or  config t  at the command prompt You can also configure a secret (encrypted) password CCNA Guide to Cisco Networking Fundamentals
Setting the Host Name The actual task of setting the host name on the Cisco Catalyst switch is identical to setting the host name on a Cisco router To configure this name, you would type: Switch(config)#hostname  name Once the host name is set, the prompt will change to reflect the name of the switch CCNA Guide to Cisco Networking Fundamentals
IP on the Switch By default, Cisco switches are not configured with IP addresses Generally speaking, a switch does not require an IP address Because switches operate mainly on Layer 2 You may want to configure an IP address for your switch so that you can manage it over the network  Also, you may need to configure an IP address for your switch if you want to implement VLANs on your network CCNA Guide to Cisco Networking Fundamentals
Configuring Switch Ports To enter interface configuration mode for the first port of a switch named Rm410HL, you would use the following commands: Rm410HL#configure terminal Rm410HL(config)#interface f0/1 Rm410HL(config-if)# To view the configuration of a port, use the  show  command CCNA Guide to Cisco Networking Fundamentals
Configuring Switch Ports (continued) Configuring the duplex mode You would use the following command to set the duplex mode: Rm410HL#configure terminal Rm410HL(config)#interface f0/24 Rm410HL(config-if)#duplex full CCNA Guide to Cisco Networking Fundamentals
Securing Switch Ports You can choose from several degrees of security on a switch First, you can configure a permanent MAC address for a specific port on your switch Second, you could define a static MAC address entry into your switching table Which maps a restricted communication path between two ports To configure port security, you first must enter the interface configuration mode CCNA Guide to Cisco Networking Fundamentals
Securing Switch Ports (continued) You can display several options by typing the following command: Rm410HL(config-if)#switchport port-security ? Options include  aging ,  mac-address ,  maximum , and  violation To turn switchport security off, use: Rm410HL(config-if)#no switchport port-security To clear the settings to include erasing the static MAC addresses, use the  clear command: Rm410HL(config-if)#clear port-security CCNA Guide to Cisco Networking Fundamentals
Summary Ethernet (CSMA/CD) is a media access method that was developed in the 1960s Stations on an Ethernet LAN must listen to the network media before transmitting to ensure that no other station is currently transmitting If two stations transmit simultaneously on the same collision domain, a collision will occur The transmitting stations must be able to recognize the collision and ensure that other stations know about it by transmitting a jam signal CCNA Guide to Cisco Networking Fundamentals
Summary (continued) The delays caused by collisions on a network can seriously affect performance when collisions exceed 5% of the traffic on the collision domain Switches do the most to divide the collision domain and reduce traffic without dividing the broadcast domain A switch microsegments unicast traffic Another way to increase the speed at which a LAN operates is to upgrade from Ethernet to Fast Ethernet Full duplex can also improve Ethernet performance CCNA Guide to Cisco Networking Fundamentals
Summary (continued) Full duplex allows frames to be sent and received simultaneously As with Fast Ethernet, full-duplex operations are only supported by devices designed for this type of communication The two types of operating systems on Cisco switches are IOS-based and set-based Configuring a switch is similar to configuring a router through the CLI Switches can provide some level of security through the use of port security commands CCNA Guide to Cisco Networking Fundamentals

More Related Content

PPT
Switch configuration
PPTX
CCNA training 101
PDF
Cisco ospf
PPT
Ccna Presentation
PPT
CCNA PPT
PPTX
End to End Security With Palo Alto Networks (Onur Kasap, engineer Palo Alto N...
PDF
MPLS Presentation
PPT
CCNA Routing Protocols
Switch configuration
CCNA training 101
Cisco ospf
Ccna Presentation
CCNA PPT
End to End Security With Palo Alto Networks (Onur Kasap, engineer Palo Alto N...
MPLS Presentation
CCNA Routing Protocols

What's hot (20)

PPT
Vlan
PPTX
ccna summer training ppt ( Cisco certified network analysis) ppt. by Traun k...
PPTX
Cisco Networking (Routing and Switching)
PPTX
CCNA ppt Day 1
PPTX
Ppt of routing protocols
PPTX
CCNA Course Training Presentation
PPTX
Routers and Routing Configuration
PPTX
Cisco router basic
PPT
CCNA SUMMER TRAINNING PPT
PPTX
OSPF Basics
PPT
Spanning tree protocol
PPTX
ccna networking ppt
PPTX
Bgp protocol
PPTX
Dynamic routing protocols (CCNA)
PPTX
Ccna PPT
PPTX
Introduction to router
PPTX
CCNA PPT
PPT
PPT
Layer 2 switching fundamentals(networking)
PDF
Cisco Router Basic Configuration
Vlan
ccna summer training ppt ( Cisco certified network analysis) ppt. by Traun k...
Cisco Networking (Routing and Switching)
CCNA ppt Day 1
Ppt of routing protocols
CCNA Course Training Presentation
Routers and Routing Configuration
Cisco router basic
CCNA SUMMER TRAINNING PPT
OSPF Basics
Spanning tree protocol
ccna networking ppt
Bgp protocol
Dynamic routing protocols (CCNA)
Ccna PPT
Introduction to router
CCNA PPT
Layer 2 switching fundamentals(networking)
Cisco Router Basic Configuration
Ad

Viewers also liked (20)

PPT
CCNA IP Addressing
PPT
CCNA Advanced Switching
PDF
Introduction to oracle primavera
PPT
CCNA Network Devices
PPT
CCNA Introducing Networks
PPT
CCNA TCP/IP
PPT
CCNA Router Startup and Configuration
RTF
CCNA Basic Switching and Switch Configuration Questions
PPT
CCNA Access Lists
PPT
CCNA Network Services
PPT
CCNA Advanced Routing Protocols
PPT
CCNA Router and IOS Basics
PPT
CCNA PPP and Frame Relay
PDF
CCNAv5 - S2: Chapter1 Introsuction to switched networks
PPT
Digital Transmission Fundamentals
PDF
CCNAv5 - S1: Chapter 1 Exploring The Network
PPT
ACIT Mumbai - CCNA Training Coourse- IP ADDRESS ASSIGNMENT
PPTX
CCNA Network Monitoring
PPTX
CCNA site-to-site connectivity security
PPTX
CCNA point to point
CCNA IP Addressing
CCNA Advanced Switching
Introduction to oracle primavera
CCNA Network Devices
CCNA Introducing Networks
CCNA TCP/IP
CCNA Router Startup and Configuration
CCNA Basic Switching and Switch Configuration Questions
CCNA Access Lists
CCNA Network Services
CCNA Advanced Routing Protocols
CCNA Router and IOS Basics
CCNA PPP and Frame Relay
CCNAv5 - S2: Chapter1 Introsuction to switched networks
Digital Transmission Fundamentals
CCNAv5 - S1: Chapter 1 Exploring The Network
ACIT Mumbai - CCNA Training Coourse- IP ADDRESS ASSIGNMENT
CCNA Network Monitoring
CCNA site-to-site connectivity security
CCNA point to point
Ad

Similar to CCNA Basic Switching and Switch Configuration (20)

PPTX
Basic switch and switch configuration.pptx
PPT
CCNA BASIC SWITCHING AND SWITCH CONFIGURATION
PPT
CCNA SWITCHING AND CONFIGURATION
PPT
Chapter 13
PPT
Chapter 4ver2
PPT
3-MACSublayer.ppt
PPT
MEDIUM ACCESS CONTROL Sublayer IN CN.ppt
PPT
IEEE Standards
PPTX
Westermo webinar: Learning the Basics of Ethernet Networking
PPT
04 - Networking Technologies.ppt
PPT
Media Access and Internetworking
PPT
Introduction_Network_lecture_ for begginers.ppt
PPT
Introduction_Network_lecture_ for begginers.ppt
PPT
Lecture 1 networking & internetworking
PPT
6 Ethernet
PDF
CCNA DUMPS 640-802
PPTX
The Basics of Industrial Ethernet Communications
PPT
NET1.PPT
Basic switch and switch configuration.pptx
CCNA BASIC SWITCHING AND SWITCH CONFIGURATION
CCNA SWITCHING AND CONFIGURATION
Chapter 13
Chapter 4ver2
3-MACSublayer.ppt
MEDIUM ACCESS CONTROL Sublayer IN CN.ppt
IEEE Standards
Westermo webinar: Learning the Basics of Ethernet Networking
04 - Networking Technologies.ppt
Media Access and Internetworking
Introduction_Network_lecture_ for begginers.ppt
Introduction_Network_lecture_ for begginers.ppt
Lecture 1 networking & internetworking
6 Ethernet
CCNA DUMPS 640-802
The Basics of Industrial Ethernet Communications
NET1.PPT

More from Dsunte Wilson (18)

PPTX
SYMANTEC ENDPOINT PROTECTION Interfacing the SEPM with Protection Center
PPTX
SYMANTEC ENDPOINT PROTECTION Performing Server and Database Management
PPTX
SYMANTEC ENDPOINT PROTECTION Configuring Replication and Failover and Load Ba...
PPTX
SYMANTEC ENDPOINT PROTECTION Advanced Monitoring and Reporting
PPTX
IBM BladeCenter Fundamentals Introduction
PPTX
SYMANTEC ENDPOINT PROTECTION Administration Introduction
PDF
Tips and Tricks of Toad for Oracle 10.6
RTF
CCNA PPP and Frame Relay Questions
RTF
CCNA Access Lists Questions
RTF
CCNA Network Services Questions
PDF
CCNA Advanced Routing Protocols Questions
PDF
CCNA Routing Protocols Questions
PDF
CCNA Router Startup and Configuration Questions
PDF
CCNA Router and IOS Basics Questions
PDF
CCNA IP Addressing
PDF
CCNA TCP/IP Questions
PDF
CCNA Network Devices Questions
PDF
CCNA Introducing Networks Questions
SYMANTEC ENDPOINT PROTECTION Interfacing the SEPM with Protection Center
SYMANTEC ENDPOINT PROTECTION Performing Server and Database Management
SYMANTEC ENDPOINT PROTECTION Configuring Replication and Failover and Load Ba...
SYMANTEC ENDPOINT PROTECTION Advanced Monitoring and Reporting
IBM BladeCenter Fundamentals Introduction
SYMANTEC ENDPOINT PROTECTION Administration Introduction
Tips and Tricks of Toad for Oracle 10.6
CCNA PPP and Frame Relay Questions
CCNA Access Lists Questions
CCNA Network Services Questions
CCNA Advanced Routing Protocols Questions
CCNA Routing Protocols Questions
CCNA Router Startup and Configuration Questions
CCNA Router and IOS Basics Questions
CCNA IP Addressing
CCNA TCP/IP Questions
CCNA Network Devices Questions
CCNA Introducing Networks Questions

Recently uploaded (20)

PDF
Architecting across the Boundaries of two Complex Domains - Healthcare & Tech...
PDF
cuic standard and advanced reporting.pdf
PDF
Spectral efficient network and resource selection model in 5G networks
PDF
Bridging biosciences and deep learning for revolutionary discoveries: a compr...
PDF
How UI/UX Design Impacts User Retention in Mobile Apps.pdf
PDF
Reach Out and Touch Someone: Haptics and Empathic Computing
PDF
CIFDAQ's Market Insight: SEC Turns Pro Crypto
PDF
Machine learning based COVID-19 study performance prediction
PDF
The Rise and Fall of 3GPP – Time for a Sabbatical?
PPTX
Detection-First SIEM: Rule Types, Dashboards, and Threat-Informed Strategy
PDF
Per capita expenditure prediction using model stacking based on satellite ima...
PDF
Advanced methodologies resolving dimensionality complications for autism neur...
PDF
Building Integrated photovoltaic BIPV_UPV.pdf
PPTX
20250228 LYD VKU AI Blended-Learning.pptx
PPTX
A Presentation on Artificial Intelligence
PPTX
VMware vSphere Foundation How to Sell Presentation-Ver1.4-2-14-2024.pptx
PPT
Teaching material agriculture food technology
PPTX
Digital-Transformation-Roadmap-for-Companies.pptx
PDF
Review of recent advances in non-invasive hemoglobin estimation
PDF
7 ChatGPT Prompts to Help You Define Your Ideal Customer Profile.pdf
Architecting across the Boundaries of two Complex Domains - Healthcare & Tech...
cuic standard and advanced reporting.pdf
Spectral efficient network and resource selection model in 5G networks
Bridging biosciences and deep learning for revolutionary discoveries: a compr...
How UI/UX Design Impacts User Retention in Mobile Apps.pdf
Reach Out and Touch Someone: Haptics and Empathic Computing
CIFDAQ's Market Insight: SEC Turns Pro Crypto
Machine learning based COVID-19 study performance prediction
The Rise and Fall of 3GPP – Time for a Sabbatical?
Detection-First SIEM: Rule Types, Dashboards, and Threat-Informed Strategy
Per capita expenditure prediction using model stacking based on satellite ima...
Advanced methodologies resolving dimensionality complications for autism neur...
Building Integrated photovoltaic BIPV_UPV.pdf
20250228 LYD VKU AI Blended-Learning.pptx
A Presentation on Artificial Intelligence
VMware vSphere Foundation How to Sell Presentation-Ver1.4-2-14-2024.pptx
Teaching material agriculture food technology
Digital-Transformation-Roadmap-for-Companies.pptx
Review of recent advances in non-invasive hemoglobin estimation
7 ChatGPT Prompts to Help You Define Your Ideal Customer Profile.pdf

CCNA Basic Switching and Switch Configuration

  • 1. CCNA Guide to Cisco Networking Fundamentals Chapter 12 Basic Switching and Switch Configuration
  • 2. Objectives Explain the technology and media access control method for Ethernet networks Explain network segmentation and basic traffic management concepts Explain basic switching concepts and the operation of Cisco switches Perform and verify switch configuration tasks Implement basic switch security CCNA Guide to Cisco Networking Fundamentals
  • 3. Ethernet Operations Ethernet A network access method (or media access method ) originated by the University of Hawaii, later adopted by Xerox Corporation And standardized as IEEE 802.3 in the early 1980s Ethernet is: Most pervasive network access method in use Most commonly implemented media access method in new LANs CCNA Guide to Cisco Networking Fundamentals
  • 4. CSMA/CD Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Ethernet contention method Any station connected to a network can transmit anytime a transmission is not present on the wire Interframe gap , or interpacket gap (IPG) After each transmitted signal, each station must wait a minimum of 9.6 microseconds before transmitting another packet CCNA Guide to Cisco Networking Fundamentals
  • 5. CSMA/CD (continued) Collisions Two stations could listen to the wire simultaneously and not sense a carrier signal Both stations might begin to transmit their data simultaneously Once a collision is detected, the first station to detect the collision transmits a 32-bit jam signal Tells all other stations not to transmit for a brief period The two stations that caused the collision use an algorithm to enter a backoff period CCNA Guide to Cisco Networking Fundamentals
  • 6. CSMA/CD (continued) Collision domain The physical area in which a packet collision might occur Routers, switches, bridges, and gateways segment networks And thus create separate collision domains The 32-bit jam signal that is transmitted when the collision is discovered prevents all stations on that collision domain from transmitting CCNA Guide to Cisco Networking Fundamentals
  • 7. CSMA/CD (continued) Broadcasts Stations on a network broadcast packets to other stations to make their presence known on the network And to carry out normal network tasks When a segment has too much broadcast traffic: Utilization increases Network performance in general suffers Simple ways to reduce broadcast traffic: Reduce the number of services on your network Limit the number of protocols in use on your network CCNA Guide to Cisco Networking Fundamentals
  • 8. CSMA/CD (continued) Broadcast storm A sudden rush of network transmissions that causes all other network communications to slow down Due to the volume of data competing for access to the same bandwidth on the communications medium One of the most common causes of broadcast storms is a network loop CCNA Guide to Cisco Networking Fundamentals
  • 9. Latency Latency , or propagation delay The length of time that is required to forward, send, or otherwise propagate a data frame Latency differs depending on the resistance offered by the transmission medium, the number of nodes And in the case of a connectivity device, the amount of processing that must be done on the packet Transmission time The amount of time it takes for a packet to be sent from one device to another CCNA Guide to Cisco Networking Fundamentals
  • 10. Latency (continued) CCNA Guide to Cisco Networking Fundamentals
  • 11. Latency (continued) Bit time Refers to the amount of time required to transmit one data bit on a network Slot time (512 bit times) An important specification that limits the physical size of each Ethernet collision domain Specifies that all collisions should be detected from anywhere in a network in less time than is required to place a 64-byte frame on the network CCNA Guide to Cisco Networking Fundamentals
  • 12. Ethernet Errors Frame size errors Short frame or runt Long frame or giant Jabber Frame check sequence (FCS) error Indicates that bits of a frame were corrupted during transmission Can be caused by any of the previously listed errors CCNA Guide to Cisco Networking Fundamentals
  • 13. Ethernet Errors (continued) Collision errors Reducing the number of devices per collision domain will usually solve the problem You can do this by segmenting your network with a router, a bridge, or a switch Late collision Occurs when two stations transmit more than 64 bytes of data frames before detecting a collision CCNA Guide to Cisco Networking Fundamentals
  • 14. Ethernet Errors (continued) Fast Ethernet Uses the same CSMA/CD as common 10BaseT Ethernet Provides ten times the data transmission rate—100 Mbps Defined under the IEEE 802.3u standard Implementations 100Base-TX 100Base-T4 100Base-FX CCNA Guide to Cisco Networking Fundamentals
  • 15. Gigabit Ethernet Recent advances in technology have allowed us to reach even higher speeds than those of Fast Ethernet Gigabit Ethernet implementations 1000Base-TX (802.3ab) 1000Base-SX (802.3z) 1000Base-LX (802.3z) 1000Base-CX (802.3z) CCNA Guide to Cisco Networking Fundamentals
  • 16. Half- and Full-Duplex Communications Half-duplex communications Devices can send and receive signals, but not at the same time Full-duplex (or duplex ) communications Devices can send and receive signals simultaneously Ethernet networks can use equipment that supports half- and full-duplex communications CCNA Guide to Cisco Networking Fundamentals
  • 17. CCNA Guide to Cisco Networking Fundamentals
  • 18. Half- and Full-Duplex Communications (continued) Benefits of using full-duplex: Time is not wasted retransmitting frames because collisions do not occur The full bandwidth is available in both directions because the send and receive functions are separate Stations do not have to wait until other stations complete their transmissions because only one transmitter is used for each twisted pair CCNA Guide to Cisco Networking Fundamentals
  • 19. Half- and Full-Duplex Communications (continued) On a Cisco Catalyst 2950 switch, you can set the duplex capabilities port-by-port The four different duplex options are: Auto Full Full-flow control Half CCNA Guide to Cisco Networking Fundamentals
  • 20. A Review of LAN Segmentation You can improve the performance of your Ethernet network By reducing the number of stations per collision domain Typically, network administrators implement bridges, switches, or routers to segment the network and divide the collision domains CCNA Guide to Cisco Networking Fundamentals
  • 21. Segmenting with Bridges Bridge Segments a network by filtering traffic at the Data Link layer Divides a network into two or more segments Only forwards a frame from one segment to another if the frame is a broadcast or has the MAC address of a station on a different segment Bridges learn MAC addresses by reading the source MAC addresses from frames As the frames are passed across the bridge CCNA Guide to Cisco Networking Fundamentals
  • 22. Segmenting with Bridges (continued) Bridging table Maps the MAC addresses on each segment to the corresponding port on the bridge to which each segment is connected Bridges increase latency, but because they effectively divide the collision domain This does not affect slot time CCNA Guide to Cisco Networking Fundamentals
  • 23. Segmenting with Bridges (continued) Remember these points: Bridges reduce collisions on the LAN and filter traffic based on MAC addresses A bridge does not reduce broadcast or multicast traffic A bridge can extend the useful distance of the Ethernet LAN The bandwidth for the new individual segments is increased Bridges can be used to limit traffic for security purposes CCNA Guide to Cisco Networking Fundamentals
  • 24. Segmenting with Routers Router Operates at layer 3 of the OSI reference model Interprets the Network layer protocol and makes forwarding decisions based on the layer 3 address Routers typically do not propagate broadcast traffic Thus, they reduce network traffic even more than bridges do Routers maintain routing tables that include the Network layer addresses of different segments CCNA Guide to Cisco Networking Fundamentals
  • 25. Segmenting with Routers (continued) When you segment a LAN with routers, they will: Decrease collisions by filtering traffic Reduce broadcast and multicast traffic by blocking or selectively filtering packets Support multiple paths and routes between them Provide increased bandwidth for the newly created segments Increase security by preventing packets between hosts on one side of the router from propagating to the other side of the router CCNA Guide to Cisco Networking Fundamentals
  • 26. Segmenting with Routers (continued) When you segment a LAN with routers, they will: (continued) Increase the effective distance of the network by creating new collision domains Provide layer 3 routing, packet fragmentation and reassembly, and traffic flow control Provide communications between different technologies, such as Ethernet and Token Ring or Ethernet and Frame Relay Have a higher latency than bridges, because routers have more to process; faster processors in the router can reduce some of this latency CCNA Guide to Cisco Networking Fundamentals
  • 27. LAN Switching Switches Similar to bridges in several ways Using a switch on a LAN has a different effect on the way network traffic is propagated CCNA Guide to Cisco Networking Fundamentals
  • 28. Segmentation with Switches Switches are often called multiport bridges Switch typically connects multiple stations individually Thereby segmenting a LAN into multiple collision domains Switches microsegment the network By connecting each port to an individual workstation Switched bandwidth Bandwidth is not shared as long as each workstation connects to its own switch port CCNA Guide to Cisco Networking Fundamentals
  • 29. Segmentation with Switches (continued) CCNA Guide to Cisco Networking Fundamentals
  • 30. CCNA Guide to Cisco Networking Fundamentals
  • 31. Segmentation with Switches (continued) Switch latency is typically higher than that of a repeater or hub Faster processors and a variety of switching techniques make switches typically faster than bridges Switches provide the following benefits: Reduction in network traffic and collisions Increase in available bandwidth per station Increase in the effective distance of a LAN by dividing it into multiple collision domains Increased security, because unicast traffic is sent directly to its destination CCNA Guide to Cisco Networking Fundamentals
  • 32. Switch Operations A switch learns the hardware address of devices to which it is attached By reading the source address of frames as they are transmitted across the switch The switch then matches the source MAC address with the port from which the frame was sent The MAC-to-switch-port mapping is stored in the switch’s content-addressable memory (CAM) The switch uses a memory buffer to store frames as it determines to which port(s) a frame will be forwarded CCNA Guide to Cisco Networking Fundamentals
  • 33. Switch Operations (continued) Types of memory buffering: Port-based memory buffering Shared memory buffering Asymmetric switching Some switches can interconnect network interfaces of different speeds Symmetric switching Switches that require all attached network interface devices to use the same transmit/receive speed CCNA Guide to Cisco Networking Fundamentals
  • 34. Switching Methods All switches base frame-forwarding decisions on a frame’s destination MAC address The three main methods for processing and forwarding frames are: Cut-through, store-and-forward, and fragment-free One additional forwarding method, adaptive cut-through forwarding A combination of the cut-through and store-and-forward methods CCNA Guide to Cisco Networking Fundamentals
  • 35. Switching Methods (continued) CCNA Guide to Cisco Networking Fundamentals
  • 36. Cut-Through Forwarding Switches that use cut-through forwarding start sending a frame immediately after reading the destination MAC address into their buffers The main benefit of cut-through forwarding is a reduction in latency The drawback is the potential for errors in the frame that the switch would be unable to detect Because the switch only reads a small portion of the frame into its buffer CCNA Guide to Cisco Networking Fundamentals
  • 37. Cut-Through Forwarding (continued) CCNA Guide to Cisco Networking Fundamentals
  • 38. Store-and-Forward Forwarding Store-and-forward switches read the entire frame, no matter how large, into their buffers before forwarding Because the switch reads the entire frame, it will not forward frames with errors The store-and-forward method has the highest latency CCNA Guide to Cisco Networking Fundamentals
  • 39. Store-and-Forward Forwarding (continued) CCNA Guide to Cisco Networking Fundamentals
  • 40. Fragment-Free Forwarding Fragment-free forwarding represents an effort to provide more error-reducing benefits than cut-through switching While keeping latency lower than does store-and-forward switching A fragment-free switch reads the first 64 bytes of an Ethernet frame And then begins forwarding it to the appropriate port(s) CCNA Guide to Cisco Networking Fundamentals
  • 41. Fragment-Free Forwarding (continued) CCNA Guide to Cisco Networking Fundamentals
  • 42. Fragment-Free Forwarding (continued) Adaptive cut-through For the most part, the adaptive cut-through switch will act as a cut-through switch To provide the lowest latency However, if a certain level of errors is detected, the switch will: Change forwarding techniques Act more as a store-and-forward switch CCNA Guide to Cisco Networking Fundamentals
  • 43. Switch User Interface Two types of operating systems are in use on Cisco switches: IOS-based and set-based You can connect to a Cisco switch in the same way you connect to a Cisco router The Cisco switch has a console port to which you can connect your laptop or PC Once you power on the switch you will be in the command-line interface You can configure anything from the command line CCNA Guide to Cisco Networking Fundamentals
  • 44. Modes and Passwords You cannot actually configure a switch until you get to enable mode To enter enable mode, type enable at the command-line prompt and then press Enter The first step in configuring a switch is to set up a password To start configuration mode, first type configure terminal or config t at the command prompt You can also configure a secret (encrypted) password CCNA Guide to Cisco Networking Fundamentals
  • 45. Setting the Host Name The actual task of setting the host name on the Cisco Catalyst switch is identical to setting the host name on a Cisco router To configure this name, you would type: Switch(config)#hostname name Once the host name is set, the prompt will change to reflect the name of the switch CCNA Guide to Cisco Networking Fundamentals
  • 46. IP on the Switch By default, Cisco switches are not configured with IP addresses Generally speaking, a switch does not require an IP address Because switches operate mainly on Layer 2 You may want to configure an IP address for your switch so that you can manage it over the network Also, you may need to configure an IP address for your switch if you want to implement VLANs on your network CCNA Guide to Cisco Networking Fundamentals
  • 47. Configuring Switch Ports To enter interface configuration mode for the first port of a switch named Rm410HL, you would use the following commands: Rm410HL#configure terminal Rm410HL(config)#interface f0/1 Rm410HL(config-if)# To view the configuration of a port, use the show command CCNA Guide to Cisco Networking Fundamentals
  • 48. Configuring Switch Ports (continued) Configuring the duplex mode You would use the following command to set the duplex mode: Rm410HL#configure terminal Rm410HL(config)#interface f0/24 Rm410HL(config-if)#duplex full CCNA Guide to Cisco Networking Fundamentals
  • 49. Securing Switch Ports You can choose from several degrees of security on a switch First, you can configure a permanent MAC address for a specific port on your switch Second, you could define a static MAC address entry into your switching table Which maps a restricted communication path between two ports To configure port security, you first must enter the interface configuration mode CCNA Guide to Cisco Networking Fundamentals
  • 50. Securing Switch Ports (continued) You can display several options by typing the following command: Rm410HL(config-if)#switchport port-security ? Options include aging , mac-address , maximum , and violation To turn switchport security off, use: Rm410HL(config-if)#no switchport port-security To clear the settings to include erasing the static MAC addresses, use the clear command: Rm410HL(config-if)#clear port-security CCNA Guide to Cisco Networking Fundamentals
  • 51. Summary Ethernet (CSMA/CD) is a media access method that was developed in the 1960s Stations on an Ethernet LAN must listen to the network media before transmitting to ensure that no other station is currently transmitting If two stations transmit simultaneously on the same collision domain, a collision will occur The transmitting stations must be able to recognize the collision and ensure that other stations know about it by transmitting a jam signal CCNA Guide to Cisco Networking Fundamentals
  • 52. Summary (continued) The delays caused by collisions on a network can seriously affect performance when collisions exceed 5% of the traffic on the collision domain Switches do the most to divide the collision domain and reduce traffic without dividing the broadcast domain A switch microsegments unicast traffic Another way to increase the speed at which a LAN operates is to upgrade from Ethernet to Fast Ethernet Full duplex can also improve Ethernet performance CCNA Guide to Cisco Networking Fundamentals
  • 53. Summary (continued) Full duplex allows frames to be sent and received simultaneously As with Fast Ethernet, full-duplex operations are only supported by devices designed for this type of communication The two types of operating systems on Cisco switches are IOS-based and set-based Configuring a switch is similar to configuring a router through the CLI Switches can provide some level of security through the use of port security commands CCNA Guide to Cisco Networking Fundamentals