预配置: R1(config-if)#int s2/1 R1(config-if)#ip add 12.0.0.1 255.255.255.0 R1(config-if)#no sh R1(config-if)#int f0/0 R1(config-if)#ip add 123.0.0.1 255.255.255.0 R1(config-if)#ip add 123.0.0.1 255.255.255.0 R1(config-if)#no sh

R2(config)#int lo0 R2(config-if)#ip add 2.2.2.2 255.255.255.0 R2(config-if)#int s2/1 R2(config-if)#no sh R2(config-if)#ip add 12.0.0.2 255.255.255.0 R2(config-if)#int f0/0 R2(config-if)#ip add 123.0.0.2 255.255.255.0 R2(config-if)#no sh

第一步:在R1上添加两条静态路由并查看路由表 R1(config)#ip route 2.2.2.0 255.255.255.0 12.0.0.2 R1(config)#ip route 2.2.2.0 255.255.255.0 123.0.0.2 2

R1#sh ip rou Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/24 is subnetted, 1 subnets S 2.2.2.0 [1/0] via 12.0.0.2 //这里为12.0.0.2 123.0.0.0/24 is subnetted, 1 subnets C 123.0.0.0 is directly connected, FastEthernet0/0 12.0.0.0/24 is subnetted, 1 subnets C 12.0.0.0 is directly connected, Serial2/1 R1# 第二步:模拟本地R1路由器上的S2/1接口death了 R1(config)#int s2/1 R1(config-if)#sh R1(config-if)#exit R1(config)#exit 第三步:查看down后的路由表 R1#sh ip rou Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/24 is subnetted, 1 subnets S 2.2.2.0 [2/0] via 123.0.0.2 //这里为123.0.0.2 123.0.0.0/24 is subnetted, 1 subnets C 123.0.0.0 is directly connected, FastEthernet0/0 R1# 第四步:模拟工程人员修好了线路并查看路由表 R1(config)#int s2/1 R1(config-if)#no sh R1(config-if)#exit R1(config)#

R1(config)#do sh ip rout Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

2.0.0.0/24 is subnetted, 1 subnets S 2.2.2.0 [1/0] via 12.0.0.2 //高兴的是12.0.0.2回来了,在这里我们向它问声好吧! 123.0.0.0/24 is subnetted, 1 subnets C 123.0.0.0 is directly connected, FastEthernet0/0 12.0.0.0/24 is subnetted, 1 subnets C 12.0.0.0 is directly connected, Serial2/1 R1(config)#