简介:IS-IS协议同标准协议OSPF一样,是一种链路状态动态路由协议,但是它比ospf做了很多优化,减少了路由类型、LSA的泛洪,在现网中的应用也十分的广泛。
实验拓扑:
实验目的:1.在R1—R5上运行IS-IS协议,R1-R6上运行RIPv2协议
2.进行路由重发布,实现R5、R6互通
3.实现域间和外部路由汇总
实验步骤:1.在R1到R6上做基本配置,以及环回口。(略)
2.运行IS-IS协议和RIP协议
R1(config)#router isis
R1(config-router)#net 49.0001.0001.0001.0001.00 //指定NSAP地址,相当于router ID
R1(config-router)#ex
R1(config)#int range f0/0 ,l0
R1(config-if-range)#ip router isis //进接口后宣告该接口下的网段
R2(config)#router isis
R2(config-router)#net 49.0001.0002.0002.0002.00
R2(config-router)#ex
R2(config)#int range f0/0 -1 ,l0
R2(config-if-range)#ip router isis
R3(config)#router isis
R3(config-router)#net 49.0000.0003.0003.0003.00
R3(config-router)#ex
R3(config)#int range f0/0 -1 ,l0
R3(config-if-range)#ip router isis
R4(config)#router isis
R4(config-router)#net 49.0000.0004.0004.0004.00
R4(config-router)#ex
R4(config)#int range f0/0 -1 ,l0
R4(config-if-range)#ip router isis
R5(config)#router isis
R5(config-router)#net 49.0002.0005.0005.0005.00
R5(config-router)#ex
R5(config)#int range f0/1 ,l0
R5(config-if-range)#ip router isis
R1(config)#router rip
R1(config-router)#version 2
R1(config-router)#no auto-summary
R1(config-router)#network 16.0.0.0
R6#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R6(config)#router rip
R6(config-router)#version 2
R6(config-router)#no auto-summary
R6(config-router)#network 16.0.0.0
R6(config-router)#network 6.6.6.6
可以对IS-IS协议作一些优化,由于ISIS协议路由器默认使用的选择级别是level 1-2,会同时发送两种LSP,这是没有必要的,十分浪费路由资源。
将R1改为level 1
R1(config)#router isis
R1(config-router)#is-type level-1 //修改路由器的路由选择级别
将R3,R4改为level 2
R3(config)#router isis
R3(config-router)#is-type level-2
R4(config)#router isis
R4(config-router)#is-type level-2
将R5的f0/1接口改为level 2
R5#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R5(config)#int f0/1
R5(config-if)#isis circuit-type level-2-only //修改接口的选择级别
3.路由重发布
R1(config)#router isis
R1(config-router)#redistribute rip ?
level-1 IS-IS level-1 routes only
level-1-2 IS-IS level-1 and level-2 routes
level-2 IS-IS level-2 routes only
metric Metric for redistributed routes
metric-type OSPF/IS-IS exterior metric type for redistributed routes
route-map Route map reference
<cr>
R1(config-router)#redistribute rip level-1
R1(config-router)#ex
R1(config)#router rip
R1(config-router)#redistribute isis ?
WORD ISO routing area tag
level-1 IS-IS level-1 routes only
level-1-2 IS-IS level-1 and level-2 routes
level-2 IS-IS level-2 routes only
metric Metric for redistributed routes
route-map Route map reference
<cr>
R1(config-router)#redistribute isis level-1 metric 2
查看一下R5的路由表
R5#show ip route
....
34.0.0.0/24 is subnetted, 1 subnets
i L2 34.0.0.0 [115/20] via 45.0.0.4, FastEthernet0/1
16.0.0.0/24 is subnetted, 1 subnets
i L2 16.0.0.0 [115/40] via 45.0.0.4, FastEthernet0/1
1.0.0.0/32 is subnetted, 1 subnets
i L2 1.1.1.1 [115/50] via 45.0.0.4, FastEthernet0/1
2.0.0.0/24 is subnetted, 1 subnets
i L2 2.2.2.0 [115/40] via 45.0.0.4, FastEthernet0/1
3.0.0.0/32 is subnetted, 1 subnets
i L2 3.3.3.3 [115/30] via 45.0.0.4, FastEthernet0/1
4.0.0.0/32 is subnetted, 1 subnets
i L2 4.4.4.4 [115/20] via 45.0.0.4, FastEthernet0/1
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
i L2 6.6.6.6 [115/40] via 45.0.0.4, FastEthernet0/1
23.0.0.0/24 is subnetted, 1 subnets
i L2 23.0.0.0 [115/30] via 45.0.0.4, FastEthernet0/1
45.0.0.0/24 is subnetted, 1 subnets
C 45.0.0.0 is directly connected, FastEthernet0/1
测试一下R5能否连通R6
R5#p 6.6.6.6
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 6.6.6.6, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 88/122/140 ms
可见,R5已经学习到R6的路由了。
4.域间路由汇总和外部路由汇总
假设在R5上有4条路由,192.168.0.1-192.168.3.1
可以在R5上进行汇总
R5(config)#router isis
R5(config-router)#summary-address 192.168.0.0 255.255.252.0
这时候,在R4上面查看路由表会发现一条汇总路由
R4#show ip r
*Mar 1 01:09:31.227: %SYS-5-CONFIG_I: Configured from console by console
R4#show ip route
....
34.0.0.0/24 is subnetted, 1 subnets
C 34.0.0.0 is directly connected, FastEthernet0/1
16.0.0.0/24 is subnetted, 1 subnets
i L2 16.0.0.0 [115/30] via 34.0.0.3, FastEthernet0/1
1.0.0.0/32 is subnetted, 1 subnets
i L2 1.1.1.1 [115/40] via 34.0.0.3, FastEthernet0/1
2.0.0.0/24 is subnetted, 1 subnets
i L2 2.2.2.0 [115/30] via 34.0.0.3, FastEthernet0/1
3.0.0.0/32 is subnetted, 1 subnets
i L2 3.3.3.3 [115/20] via 34.0.0.3, FastEthernet0/1
4.0.0.0/32 is subnetted, 1 subnets
C 4.4.4.4 is directly connected, Loopback0
5.0.0.0/32 is subnetted, 1 subnets
i L2 5.5.5.5 [115/20] via 45.0.0.5, FastEthernet0/0
6.0.0.0/32 is subnetted, 1 subnets
i L2 6.6.6.6 [115/30] via 34.0.0.3, FastEthernet0/1
23.0.0.0/24 is subnetted, 1 subnets
i L2 23.0.0.0 [115/20] via 34.0.0.3, FastEthernet0/1
12.0.0.0/24 is subnetted, 1 subnets
i L2 12.0.0.0 [115/30] via 34.0.0.3, FastEthernet0/1
45.0.0.0/24 is subnetted, 1 subnets
C 45.0.0.0 is directly connected, FastEthernet0/0
i L2 192.168.0.0/22 [115/20] via 45.0.0.5, FastEthernet0/0
这样可以节省路由器的资源。
同样的,假设在R6上有4条路由172.16.0.1-172.16.3.1
可以在R1上进行路由汇总
R1(config)#router isis
R1(config-router)#summary-address 172.16.0.0 255.255.252.0 level-1
注意:在对外部路由进行汇总的时候,最后要加上level-x ,否则无效
在R2上查看一下路由汇总是否生效。
R2#show ip route
.....
34.0.0.0/24 is subnetted, 1 subnets
i L2 34.0.0.0 [115/20] via 23.0.0.3, FastEthernet0/0
16.0.0.0/24 is subnetted, 1 subnets
i L1 16.0.0.0 [115/10] via 12.0.0.1, FastEthernet0/1
1.0.0.0/32 is subnetted, 1 subnets
i L1 1.1.1.1 [115/20] via 12.0.0.1, FastEthernet0/1
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
3.0.0.0/32 is subnetted, 1 subnets
i L2 3.3.3.3 [115/20] via 23.0.0.3, FastEthernet0/0
4.0.0.0/32 is subnetted, 1 subnets
i L2 4.4.4.4 [115/30] via 23.0.0.3, FastEthernet0/0
5.0.0.0/32 is subnetted, 1 subnets
i L2 5.5.5.5 [115/40] via 23.0.0.3, FastEthernet0/0
6.0.0.0/32 is subnetted, 1 subnets
i L1 6.6.6.6 [115/10] via 12.0.0.1, FastEthernet0/1
23.0.0.0/24 is subnetted, 1 subnets
C 23.0.0.0 is directly connected, FastEthernet0/0
172.16.0.0/22 is subnetted, 1 subnets
i L1 172.16.0.0 [115/10] via 12.0.0.1, FastEthernet0/1
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, FastEthernet0/1
45.0.0.0/24 is subnetted, 1 subnets
i L2 45.0.0.0 [115/30] via 23.0.0.3, FastEthernet0/0
i L2 192.168.0.0/22 [115/40] via 23.0.0.3, FastEthernet0/0
汇总完毕,实验结束