IP1 (3b) IP Routing Dynamic Routing Protocols (Part 2) Hervé TREMEUR AT&T Business System International network solutions
[email protected] IP1 Training
CISCO router introduction
Contents 1. Interior Gateway Routing Protocol (IGRP) y y y y y y
RIP Message Format Operation of IGRP Operation of IGRP (cont.) IGRP Metrics IGRP Packet Format Configuring IGRP
CISCO router introduction
Contents (Cont.) 2. Routing Information Protocol Version 2 (RIPv2) y y y y y
Operation of RIP version2 RIP v2 Message format Compatibility with RIP v1 Compatibility with RIP v1 (cont.) RIP v2 (VLSM)
CISCO router introduction
Interior Gateway Routing Protocol (IGRP) Answers to RIP limitations y y y y y
Supports up to 255 hops in diameter Composite metric from a variety of route variables Unequal cost load balancing Longer update period More efficient update packet format
IGRP limitations y Cisco propriatary protocol ( run on Cisco platforms only) y Adapted to only IP and ISO Connectionless Network Protocol (CLNS)
CISCO router introduction
Operation of IGRP Shares many operational characteristics with RIP y y y y y
Classfull distance vector protocol Periodically broadcast its entire route table Split horizon with poison reverse Triggered Updates Holddown timers
Unlike RIP accessed via UDP, IGRP access via IP Layer as protocol 9. y IGRP uses concept of autonomous system (AS)
CISCO router introduction
Operation of IGRP (cont.) Within updates , IGRP classifies route entries into 3 categories :
y Interior route (path to a subnet), interior to the major network y System route (path to a network) which has been summarized by a network boundary router
y Exterior route(path to network flagged as default network) y Classifying a default network as a an external route is unique to IGRP or EIGRP
IGRP timers
y IGRP update period is 90 seconds y Invalid timer set to 270 seconds y If a destination becomes unavailable or of the next-hop increases the metric enough to cause a triggered update , the route is placed in holddown for 280 seconds
CISCO router introduction
IGRP Metrics y Bandwidth : 10 000 000 / lowest configured bandwidth on the path y Delay : sum of the configured delays expressed in units of 10 microseconds
y Reliability : number between 0 and 255 reflects total error rates y Load : number between 0 and 255reflects the total load ofg the interfaces along the path
y MTU : smallest MTU of any link along the route
CISCO router introduction
IGRP Packet Format y IGRP packet size is 12 +(104 x 14) = 1468 + IP header (32)= 1500 B 0
16
8 Version
OP/code
Edition
Autonomous System Number Number of system routes
Number of interior Routes
checksum
Number of exterior Routes Destination
Delay Bandwidth
Delay Bandwidth load
31
MTU Hop count
Destination
Reliability Destination
Delay
MTU
Bandwidth
MTU
reliability . . .
load
Hop count
CISCO router introduction
Configuring IGRP Basic IP configuration 192 .168.1 .1 / 27
R outer 1 1 92.1 68.83 .2 44 / 24
R outer 2 1 92.16 8.83.1 / 24
19 2.168 .1.66 / 27
1 92.16 8.1.193 / 27
10 .1 .5.1 / 1 6
192 .1 68.1.6 5 / 2 7 1 72.1 7.2.1 / 2 4
R outer 3
192 .1 68.1.1 94 / 27
R outer 5 17 2.17.2 .2 /2 4
10.4.7 .1 / 24
R o uter 4
Router2(config)# router igrp 10
Router4(config)# router igrp 10
Router2(config-router)# network 172.17.0.0
Router2(config-router)# network 172.17.0.0
Router2(config-router)# network 192.168.1.0
Router2(config-router)# network 10.0.0.0
Router2(config-router)# network 192.168.83.0
CISCO router introduction
Configuring IGRP Unqual-Cost Load Balancing R o u te r 6
1 9 2 .1 6 8 .1 .1 / 2 7
R o u te r 1 1 9 2 .1 6 8 .8 3 .2 4 4 / 2 4
1 9 2 .1 6 8 .1 .6 7 / 2 7
R o u te r 2 1 9 2 .1 6 8 .8 3 .1 / 2 4
1 9 2 .1 6 8 .1 .6 6 / 2 7
1 9 2 .1 6 8 .1 .1 9 3 / 2 7
1 0 .1 .5 .1 / 1 6
1 7 2 .1 8 .2 .1 / 2 4 1 7 2 .1 7 .2 .1 / 2 4 1 9 2 .1 6 8 .1 .6 5 / 2 7
1 9 2 .1 6 8 .1 .1 9 4 / 2 7
R o u te r 3
R o u te r 5
1 7 2 .1 8 .2 .2 / 2 4
1 7 2 .1 7 .2 .2 /2 4
1 0 .4 .7 .1 / 2 4
Router2(config)# router igrp 10
R o u te r 4
Router2(config-router)# network 172.17.0.0 Router2(config-router)# network 192.168.1.0 Router2(config-router)# network 192.168.83.0 Router2(config-router)# network 172.17.0.0 Router2(config-router)# variance 5
Router4(config)# router igrp 10 Router4(config-router)# network 172.17.0.0 Router4(config-router)# network 10.0.0.0 Router4(config-router)# network 172.17.0.0 Router2(config-router)# variance 5
CISCO router introduction
Routing Information Protocol Version 2 RIPv1 + extensions y y y y
Subnet Masks carried with each route entry (VLSM) Authentication of Routing Updates External Route Tags Multicast Route updates
CISCO router introduction
Operation of RIP version2 y Same timers and stability features as in RIP v1 y Different broadcast Updates y RIPv2 mullticasts updates to other RIP v2 speaking routers using the reserved class D address 224.0.0.9
CISCO router introduction
RIP v2 Message format y RIP V2 takes advantages of the unused fields of the version 1 0
8
Command
16
Version Must Be Zero Route Tag Family of Net IP Address of Net 1 Subnet Mask Next Hop Metric (distance to Net 1) Family of Net 2 Route Tag IP Address of Net 2 Subnet Mask Next Hop Metric (Distance to Net 2) . . .
31
CISCO router introduction
Compatibility with RIP v1 Compatibility switch with 4 settings allows Versions 1 and 2 to interoperate y RIP1 : only RIPv1 are transmitted y RIP1 compatibility : which causes RIPv2 to broadcasts updates instead of Multicast them (RIPv1 can understand them)
y RIP2 : in which RIPv2 are mulicast to destination address 224.0.0.9 y None : no updates y Compatibility switch configurable on a per interface basis Receive control switch y RIP1 : only RIPv1 y RIP2 only y Both y None
CISCO router introduction
Compatibility with RIP v1 (cont.) Configuration 192 .168.1 .1 / 27
R outer 1 1 92.1 68.83 .2 44 / 24
Router 2 RIP V2
R outer 2 1 92.16 8.83.1 / 24
19 2.168 .1.66 / 27
1 92.16 8.1.193 / 27
Router 3 RIP V1
10 .1 .5.1 / 1 6
192 .1 68.1.6 5 / 2 7 1 72.1 7.2.1 / 2 4
R outer 3
192 .1 68.1.1 94 / 27
R outer 5 17 2.17.2 .2 /2 4
10.4.7 .1 / 24
Router2(config)# interface E0
R o uter 4
Router2(config)# router rip Router2(config-router)# version 2
Router2(config-if)# ip rip send version 1
Router2(config-router)# network 172.17.0.0
Router2(config-if)# ip rip receive version 1
Router2(config-router)# network 192.168.1.0 Router2(config-router)# network 192.168.83.0
CISCO router introduction
RIP v2 (VLSM) 192.168.50.0 ETHERNET
10 Hosts 100 Hosts Serial Link
2 Hosts Token-ring
ETHERNET 50 Hosts
ETHERNET 20 Hosts
y RIPv2 and VLSM can be used to allow the class C 192.168.50.0 to accommodate this internetwork and the hosts on each on the data link.
