通过本实验，需要掌握以下技能：
1) 路由表的概念 2) IP route 命令的使用 3) 根据需求正确配置静态路由 4) 根据需求使用默认路由
拓扑结构
实现, 2.2.2.0/24, /24网络之间能互相通信
实验步骤 n 步骤1：在各路由器上配置IP 地址、保证直连链路的连通性 R2(config)#int loopback0 R2(config-if)#ip address 2.2.2.2 R2(config)#int s1/0 R2(config-if)#ip address 12.1.1.2 R2(config-if)#no shutdown
R1(config)#int loopback0 R1(config-if)#ip address 1.1.1.1 R1(config)#int s1/0 R1(config-if)#clock rate 64000 R1(config-if)#ip address R1(config-if)#no shutdown R1(config)#int s1/1 R1(config-if)#clock rate 64000 R1(config-if)#ip address 13.1.1.1 R1(config-if)#no shutdown
R3(config)#int loopback0 R3(config-if)#ip address R3(config)#int s1/1 R3(config-if)#ip address 13.1.1.3 R3(config-if)#no shutdown
n 步骤2：R2 上配置静态路由 R2(config)#ip route 1.1.1.0 s1/0 // 下一跳为接口形式，s1/0是点到点的链路，注意应该是R2上的s1/0 R2(config)#ip route // 下一跳为IP地址形式，是R1上的IP地址 n 步骤3：R1 上配置静态路由 R1(config)#ip route 2.2.2.0 s1/0 R1(config)#ip route s1/1
n 步骤4：R3 上配置静态路由 R3(config)#ip route 1.1.1.0 s1/1 R3(config)#ip route 2.2.2.0 s1/1
实验调试 n 在R2,R1,R3上查看路由表 R2#show ip route 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
1.0.0.0/24 is subnetted, 1 subnets S 1.1.1.0 is directly connected, Serial1/0 2.0.0.0/24 is subnetted, 1 subnets C 2.2.2.0 is directly connected, Loopback0 3.0.0.0/24 is subnetted, 1 subnets S [1/0] via 12.0.0.0/24 is subnetted, 1 subnets C is directly connected, Serial1/0
R1#show ip route
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
1.0.0.0/24 is subnetted, 1 subnets C 1.1.1.0 is directly connected, Loopback0 2.0.0.0/24 is subnetted, 1 subnets S 2.2.2.0 is directly connected, Serial1/0 3.0.0.0/24 is subnetted, 1 subnets S is directly connected, Serial1/1 12.0.0.0/24 is subnetted, 1 subnets C is directly connected, Serial1/0 13.0.0.0/24 is subnetted, 1 subnets C 13.1.1.0 is directly connected, Serial1/1
R3#show ip route 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
1.0.0.0/24 is subnetted, 1 subnets S 1.1.1.0 is directly connected, Serial1/1 2.0.0.0/24 is subnetted, 1 subnets S 2.2.2.0 is directly connected, Serial1/1 3.0.0.0/24 is subnetted, 1 subnets C is directly connected, Loopback0 13.0.0.0/24 is subnetted, 1 subnets C 13.1.1.0 is directly connected, Serial1/1
n 在各路由器上ping其它路由器的环回口 R2#ping 1.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 4/20/60 ms R2#ping Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: ..... Success rate is 0 percent (0/5) R2#ping source 2.2.2.2
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds: Packet sent with a source address of 2.2.2.2 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 12/44/92 ms
【实验结论】 1) 各路由器上ping loopback地址所在的直连网段都能通 2) R1上ping 2.2.2.2和都能通 3) R2上ping 和R3上ping 2.2.2.2是不通的，但R2上ping source 2.2.2.2和R3上ping 2.2.2.2 source 能通 【提示】 用ping测试不设置源IP地址，默认以接口地址为源地址，查看R3的路由表，没有到目标网段的路由条目，故R3无法响应R2的报文 【解决方法】 R3(config)#ip route s1/1 R3(config)#ip route 0.0.0.0 0.0.0.0 s1/1
