静态路由
拓扑：
Lo0:1.1.1.1/24---R1---------12.12.12.0/24--------R2------L00:2.2.2.2/24
设备配置：
[R1]int s0/2/0
[R1-Serial0/2/0]ip add 12.12.12.1 255.255.255.0
[R1-Serial0/2/0]undo shutdown
[R1]int lo0
[R1-LoopBack0]ip add 1.1.1.1 255.255.255.0
[R1]ip route-static 2.2.2.0 255.255.255.0 12.12.12.2
[R2]int s0/2/0
[R2-Serial0/2/0]ip add 12.12.12.2 255.255.255.0
[R2-Serial0/2/0]undo shutdown
[R2-Serial0/2/0]quit
[R2]int lo0
[R2-LoopBack0]ip add 2.2.2.2 255.255.255.0
[R2]ip route-static 1.1.1.0 255.255.255.0 12.12.12.1
查看R1的路由表：
[R1]display ip routing-table
Routing Tables: Public
Destinations : 7 Routes : 7
Destination/Mask Proto Pre Cost NextHop Interface
1.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0
2.2.2.0/24 Static 60 0 12.12.12.2 S0/2/0
12.12.12.0/24 Direct 0 0 12.12.12.1 S0/2/0
12.12.12.1/32 Direct 0 0 127.0.0.1 InLoop0
12.12.12.2/32 Direct 0 0 12.12.12.2 S0/2/0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
查看R2的路由表：
[R2]display ip routing-table
Routing Tables: Public
Destinations : 7 Routes : 7
Destination/Mask Proto Pre Cost NextHop Interface
1.1.1.0/24 Static 60 0 12.12.12.1 S0/2/0
2.2.2.2/32 Direct 0 0 127.0.0.1 InLoop0
12.12.12.0/24 Direct 0 0 12.12.12.2 S0/2/0
12.12.12.1/32 Direct 0 0 12.12.12.1 S0/2/0
12.12.12.2/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
测试连通性：
[R2]ping 1.1.1.1
PING 1.1.1.1: 56 data bytes, press CTRL_C to break
Reply from 1.1.1.1: bytes=56 Sequence=1 ttl=255 time=15 ms
Reply from 1.1.1.1: bytes=56 Sequence=2 ttl=255 time=4 ms
Reply from 1.1.1.1: bytes=56 Sequence=3 ttl=255 time=4 ms
Reply from 1.1.1.1: bytes=56 Sequence=4 ttl=255 time=5 ms
Reply from 1.1.1.1: bytes=56 Sequence=5 ttl=255 time=2 ms
--- 1.1.1.1 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 2/6/15 ms
把上的静态路由删除换为默认路由：
[R1]ip route-static 0.0.0.0 0.0.0.0 12.12.12.2
[R2]ip route-static 0.0.0.0 0.0.0.0 12.12.12.1
[R2]ping 1.1.1.1
PING 1.1.1.1: 56 data bytes, press CTRL_C to break
Reply from 1.1.1.1: bytes=56 Sequence=1 ttl=255 time=25 ms
Reply from 1.1.1.1: bytes=56 Sequence=2 ttl=255 time=14 ms
Reply from 1.1.1.1: bytes=56 Sequence=3 ttl=255 time=25 ms
Reply from 1.1.1.1: bytes=56 Sequence=4 ttl=255 time=4 ms
Reply from 1.1.1.1: bytes=56 Sequence=5 ttl=255 time=15 ms
--- 1.1.1.1 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 4/16/25 ms