Current configuration : 732 bytes ! version 12.1 service timestamps debug uptime service timestamps log uptime no service passWord-encryption ! hostname R1 ! ip subnet-zero ! interface Ethernet0 ip address 172.16.1.1255.255.255.0 no keepalive ! interface Serial0 ip address 172.16.12.1255.255.255.0 clockrate 500000 bandwidth 500 ! interface Serial1 ip address 172.16.13.1255.255.255.0 clockrate 500000 bandwidth 500 ! router igrp 100 network 172.16.0.0 ! ip classless ip http server ! ! line con 0 exec-timeout 0 0 logging synchronous line aux 0 line vty 0 4 password cisco login ! end 第2段:R2配置清单 R2#sh run Building configuration... Current configuration : 558 bytes ! version 12.1 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname R2 ! ip subnet-zero no ip finger ! interface Ethernet0 ip address 172.16.2.2 255.255.255.0 no keepalive ! interface Serial0 ip address 172.16.12.2 255.255.255.0 bandwidth 500 ! interface Serial1 ip address 172.16.23.2 255.255.255.0 clockrate 64000 bandwidth 64 ! router igrp 100 network 172.16.0.0 ! ip classless ip http server ! line con 0 logging synchronous transport input none line aux 0 line vty 0 4 ! end 第3段:R3配置清单 R3#sh run Building configuration... Current configuration : 623 bytes ! version 12.1 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname R3 ! no logging console ip subnet-zero no ip finger ! interface Ethernet0 ip address 172.16.33 255.255.255.0 no keepalive ! interface Serial0 ip address 172.16.13.3 255.255.255.0 bandwidth 500 interface Serial 1 ip address 172.16.23.3 255.255.255.0 bandwidth 64 ! router igrp 100 network 172.16.0.0 ! ip classless ip http server ! line con 0 logging synchronous transport input none line aux 0 line vty 0 4 ! end 第4段:show和debug R1#sh ip route igrp 172.16,0,0/24 is subnetted, 6 subnets I 172.16.23.0 [100/160250] via 172.16.12.2, 00:00:59, Serial0 [100/160250] via 172.16.13.3, 00:00:30, Serial1 I 172.16.2.0 [100/22100] via 172.16.12.2, 00:00:59, Serial0 I 172.16.3.0 [100/22100] via 172.16.13.3, 00:00:30, Serial1 R1# Term_Server>2 [Resuming connection 1 to R2 ... ] R2#sh ip route igrp 172.16.0.0/24 is subnetted, 6 subnets I 172.16.13.0 [100/24000] via 172.16.12.1, 00:00:21, Serial0 I 172.16.1.0 [100/22100] via 172.16.12.1, 00:00:21, Serial0 I 172.16.3.0 [100/24100] via 172.16.12.1, 00:00:21, Senal0 R2# Term_Server>3 [Resuming connection 1 to R3 ... ] R3#sh ip route igrp 172.16.0.0/24 is subnetted, 6 subnets I 172.16.12.0 [100/24000] via 172.16.13.1, 00:00:47, Serial0 I 172.16.1.0 [100/22100] via 172.16.13.1, 00:00:47, Serial0 I 172.16.2.0 [100/24100] via 172.16.13.1, 00:00:47, Serial0 R3#sh ip PRof Routing Protocol is "igrp 100" Sending updates every 90 seconds, next due in 25 seconds Invalid after 270 seconds, hold down 280, flushed after 630 Outgoing update filter list for all interfaces is Incoming update filter list for ail interfaces is Default networks flagged in outgoing updates Default networks accepted from incoming updates IGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 IGRP maximum hopcount 100 IGRP maximum metric variance 1 Redistributing: igrp 100 Routing for Networks: 172.16.0.0 Routing Information Sources: Gateway Distance Last Update 172.16.23.2 100 00:00:28 172.16.13.1 100 00:00:09 Distance: (default is 100)
R3#ping 172.16.12.1
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.12.1, timeout is 2 seconds: !!!!! SUCcess rate is 1 (X) percent (5/5), round-trip min/avg/max == 8/12/28 ms R3#trace 172.16.12.1 Type escape sequence to abort. Tracing the route to 172.16.12.1 1 172.16.13.1 4 msec 4 msec * (1)与RIP协议配置不同的是，在IGRP协议的配置申，我们没有一步步地给出配置过程，而是给出了操作完成后的配置清单。通过各路由器的配置清单可以清楚地了解到它们的配置。 (2)bandwidth500命令设置对应接口的速率为500kbit/s，bandwidth64则设置对应接口速率为64kbit/s。在RIP协议的配置中，这个命令对于路由选择没有实际意义，因为RIP是以跳数为惟一度量值的;而对IGRP协议，这个命令很重要，只有加入这个命令，所计算出的路由表才能真实反映不同路径的带宽情况。带宽是IGRP协议的度量值之一。 (3)使用router igrp命令创建IGRP路由进程，后面的"100"是自治系统号。3个路由器必须具有相同的自治系统号，否则彼此的路由信息将不被互相传递和学司。 (4)声明网段的方法与RIP相同，即使用network命令，后面写入网络地址。 (5)在第4段中，使用show ip route igrp命令单独显示了各路由器上由IGRP学习到的路由表项。 在[100/24100]、[100/160250]的100是IGRP协议的治理距离，24100和160250是对应表项的度量值 (Metric)，度量值越小表明对应的路径越好。 (6)show ip protocol命令显示了IGRP协议的配置信息和统计信息。其中有各种计日寸器信息、所路由的网络、路由信息源、缺省治理距离等信息。IGI让的默认治理距离是100。 (7)在实验的最后，使用ping和trace命令测试了网络的连通性，表明IGRP协议工作正常，实现了全网在IP层的连通性。
