CCNA ppt Day 5
- 1. Dynamic Routing • With the help of Routing Protocols Router find the way by itself is called Dynamic Routing • Routing Protocols are divided into two:- • Interior gateway protocol • Exterior gateway protocol Interior gateway Protocols are used in an autonomous system and Exterior gateway protocols are to configure ASBR. • Ex: of Interior Gateway- RIP, IGRP, EIGRP, OSPF • Ex: of Exterior Gateway- BGP, IS-IS • Terms in Dynamic routing…
- 2. Autonomous System • A group of Routers in a single administrative domain is called autonomous system. • Autonomous systems consisting of same number can communicate. • Different autonomous system is inter connected using ASBR (Autonomous System Boundary Router)
- 3. Administrative Distance • If a network gets an information from a source through multiple Router, it selects the Router having lowest Administrative Distance value. • RIP- 120 • IGRP- 100 • OSPF-110 • EEGRP- 90
- 4. DVP (Distance Vector Protocol) • Factors which is used in DVP are Distance & Direction for communication between two networks • Each Router has a routing table which it shares with other Routers i.e., each Router updates its routing table in every periodic timers • If one of the network under a Router becomes down all other updates their routing table. • Due to this convergence a looping occurs called Routing Loop. • This is not applicable in most cases.
- 5. Maximum Hop Count • It is a loop avoiding technique • It counts hop in every table • After a critical no: of hop it avoids before looping occurs
- 6. Split Horizon • It is also a loop avoiding system • If a Router R1 updates a network information from another Router R2 • Then that network information is not updates back in the R1
- 7. Reverse Poison • The Router under which the network is down produces a signal called reverse poison. • It shares with other Routers. • It removes the information regarding the network which is down on the other Routers.
- 8. Hold down Timer • If a network is down under a flappy situation under a Router, the hold down timer waits for a particular time period. • After that it removes the information regarding the down network in the other Routers.
- 9. RIP (Routing Information Protocol) • RIP is a universal protocol. • Could be configured in any Router. • Its AD value is 120. • It is DVP. • RIP’s metric is hop count. • RIP’s hop count is 15, so it supports up to 16 Routers. • It has two versions, RIP version 1 and RIP version 2 • Providing sub netted IP’s for Router in order to avoid wastage of IP is called RIP version 2. • RIP version 2 is classless routing protocol.
- 10. RIP Configuration An example of a routing configuration is: Router(config)#Router rip Router(config-Router)#network 172.16.0.0
- 11. Verifying RIP
- 12. RIP Timers • Route update timer Sets the interval (typically 30 seconds) between periodic routing updates • Route invalid timer Determines the length of time (180 seconds) before a Router determines that a route has become invalid • Hold-down timer This sets the amount of time during which routing information is suppressed. This continues until either an update packet is received with a better metric or until the hold-down timer expires. The default is 180 seconds • Route flush timer Sets the time between a route becoming invalid and its removal from the routing table (240 seconds). • Syntax:- Router(config-Router)#timers basics 10 20 30 40
- 13. Debugging
- 14. Passive Interface Passive-interface command prevents RIP update broadcasts from being sent out a defined interface, but same interface can still receive RIP updates R1#config t R1(config)#Router rip R1(config-Router)#network 192.168.10.0 R1(config-Router)#passive-interface serial 0
- 15. IP Routing Table
- 16. RIP version 1 vs. RIP version 2 R1# config t R1(config)# )#Router rip R1(config)#network 192.168.10.0 R1(config)#network 192.168.20.0 R1(config)#version 2
- 17. Floating type AD value • Configured two protocols in a network RIP & Static, but should work only on RIP. • For that we increase Static’s AD value larger than the RIP. • If RIP is down it should work on Static. • Syntax:- Router(config)#ip route ‘unknown network’ ‘subnet mask’ ‘next hop address’ ‘ad value’
- 18. IGRP (Interior Gateway Protocol) • It is a distance vector protocol • It is a cisco proprietary protocol • Only works on cisco devices • Its AD value is 100 • IGRP metric is composite metric • There are 5 factors to find the direction 1. Bandwidth 2. Delay 3. Load 4. Reliability 5. MTU (Maximum Transmission Unit) • Default Hop count is 100 • It could be extended up to 255.
- 19. Configuring IGRP
- 20. IGRP Timers • Update timers these specify how frequently routing-update messages should be sent. The default is 90 seconds. • Invalid timers These specify how long a Router should wait before declaring a route invalid if it doesn’t receive a specific update about it. The default is 3*90 = 270. • Hold-down timers These specify the hold-down period. The default is three times the update timer period plus 10 seconds. 280 seconds • Flush timers These indicate how much time should pass before a route should be flushed from the routing table. The default is seven times the routing update period. If the update timer is 90 seconds by default, then 7 × 90 = 630 seconds elapse before a route will be flushed from the route table.
- 21. EIGRP (Enhanced Interior Gateway Routing Protocol) • EIGRP is a Cisco proprietary protocol • Its is a hybrid protocol • It has Features of Link state and DVP • It maintains three tables:- 1. Neighbor ship- This table keeps the information of another Router which is its neighbor. 2. Topology- It keeps the information of all possible routes from one network to another. 3. Routing- This keeps the information of best path from one n/w to another. • It has AD value of 90 • Distance is calculated by composite metric • Its maximum hop count is 100, extendable up to 255
- 22. Efficient Neighbor Discovery • Hello packet is used to establish neighbor ship by Router. • Every 5 sec Hello packet is sent to 224.0.0.10 • When another Router receives the hello packet, it checks whether it is in same network or in same AS no: or same K values. • Then only it sends acknowledgement and Accepts the Router as its neighbor • This process is called efficient neighbor discovery.
- 23. RTP (Reliable Transport Protocol ) • This protocol is enhanced with EIGRP • If a Router is down and another Router does not receives any acknowledgement • It sends the hello packet as unicast 16 times to the Router • Still if does not receives any acknowledgement, the it removes the information regarding the Router from neighbor ship table.
- 24. PDM (Protocol Dependent Module) It is module which helps to communicate multiple or different types of network protocol or IOS
- 25. Reporter • If R1 receives the information regarding R3 network from R2. • Then R2 is the reporter. Reported Distance • The Distance from Reporter to R3 network is called Reported Distance. Feasible Distance The distance from R1 to the Reporter + the Reported Distance is called Feasible Distance or Actual Distance.
- 26. Successor • Routing table which consist of information regarding the best path from one network to another is called Successor Feasible Successor • The second best path in Routing table is called Feasible Successor.
- 27. DUAL (Diffusing Update Algorithm) • All route computations in EIGRP are handled by DUAL • One of DUAL's tasks is maintaining a table of loop-free paths to every destination. • It is used in EIGRP . • It manages the best path and best second path.
- 28. Configuring EIGRP Router(config)#router eigrp autonomous-system Router(config-router)#network ‘network address’
- 29. EIGRP & IGRP Metric Calculation
- 30. To view Tables • Neighbor ship table- Router#show ip eigrp neighbors • Topology table- Router#show ip eigrp topology • Routing- Router#show ip route
- 31. Summarization • Super netting is the reverse process of sub netting • It is the process of converting multiple network to a single network • There are two types:- 1. Automatic 2. Manual • Automatic Summarization is enabled in default Cisco router • It is summarized to parent network. • Syntax:- Router(config-router)#no auto-summary • Summary address is given to the interface at which all the updates are sharing. • Router(config-if)#ip summary –address eigrp 100 ‘address’ ‘mask’
- 32. Loopback Interface • Virtual or imaginary interface configuration for router • Syntax:- Router(config)#interface loopback 0 Router(config-if)#ip address ‘address’ ‘mask’ Router(config-if)#no shut