CCNA学习笔记12--静态选择路由（实验）

实验拓扑：

实验目的：

掌握静态选择路由的配置和理解最长匹配原则

实验步骤：

1.基本配置

2.配置对应的IP地址

3. 做相关配置，能让R1通过R2能够ping通R3的环回口地址

R1(config)#ip route 33.1.1.0 255.255.255.0 12.1.1.2

R2(config)#ip route 33.1.1.0 255.255.255.0 23.1.1.3

R3(config)#ip route 12.1.1.0 255.255.255.0 23.1.1.2

R1#ping 33.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 33.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

R1#traceroute 33.1.1.1

Type escape sequence to abort.

Tracing the route to 33.1.1.1

VRF info: (vrf in name/id, vrf out name/id)

  1 12.1.1.2 0 msec 0 msec 1 msec

  2 23.1.1.3 0 msec *  1 msec

4. 需求：R1去往33.1.1.1直接通过R1->R3即可

         R1去往33.1.1.2, 33.1.1.3, 33.1.1.4需要R1->R2->R3

R1(config)#ip route 33.1.1.1 255.255.255.255 13.1.1.3

R1#show ip route

      12.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        12.1.1.0/24 is directly connected, Ethernet0/1

L        12.1.1.1/32 is directly connected, Ethernet0/1

      13.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        13.1.1.0/24 is directly connected, Ethernet0/0

L        13.1.1.1/32 is directly connected, Ethernet0/0

      33.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

S        33.1.1.0/24 [1/0] via 12.1.1.2

S        33.1.1.1/32 [1/0] via 13.1.1.3

R1#traceroute 33.1.1.1

Type escape sequence to abort.

Tracing the route to 33.1.1.1

VRF info: (vrf in name/id, vrf out name/id)

  1 13.1.1.3 1 msec *  1 msec

R1#traceroute 33.1.1.2

Type escape sequence to abort.

Tracing the route to 33.1.1.2

VRF info: (vrf in name/id, vrf out name/id)

  1 12.1.1.2 3 msec 0 msec 0 msec

  2 23.1.1.3 1 msec *  1 msec

解释说明：可以发现通往33.1.1.1的路由有两条，分别是33.1.1.0/24和33.1.1.1/32，实验可知通往33.1.1.1的路由是选择的是33.1.1.1/32。根据就是：最长匹配原则。（最长匹配原则实现了处于同一网段的IP包选择不同的出口）