ISIS与EIGRP

 

ISIS重发布进EIGRP

各个区域配置好后，在R1上查看路由表

R1#sh ip route

     2.0.0.0/24 is subnetted, 1 subnets

i L1    2.2.2.0 [115/20] via 12.1.1.2, Serial1/0

D    3.0.0.0/8 [90/2297856] via 13.1.1.3, 00:02:25, Serial1/2

     12.0.0.0/24 is subnetted, 1 subnets

C       12.1.1.0 is directly connected, Serial1/0

     13.0.0.0/24 is subnetted, 1 subnets

C       13.1.1.0 is directly connected, Serial1/2

可以看到在R1上已经学习到ISIS区域的路由，同时也学习到EIGRP区域的的路由，需要特别注意的是ISIS的路由是以lever-1存在的

 

在R1上做如下配置

R1(config)#router eigrp 1

R1(config-router)#redistribute isis

 

在R3查看路由表

R3#sh ip route

     3.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C       3.3.3.0/24 is directly connected, Loopback0

D       3.0.0.0/8 is a summary, 00:04:53, Null0

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

C       13.1.1.0/24 is directly connected, Serial1/2

D       13.0.0.0/8 is a summary, 00:04:53, Null0

 

在R1上查看已配置的重发布内容

R1#sh run | b r e

router eigrp 1

 redistribute isis level-2

 network 13.1.1.0 0.0.0.255

发现默认就是重发布level-2，但是R1上只存在level-1的isis路由，所以需要手工指定，同时重发布进EIGRP时还需要手工指定K值

 

做如下配置

R1(config)#router eigrp 1

R1(config-router)#redistribute isis level-1 metric 1500 1000 255 1 1500

 

在R3上查看路由表，发现已经有2.0.0.0/24的路由，但是没有ISIS区域那条直连路由，这是ISIS协议的缺陷，他不会发布直连路由

R3#sh ip route

     2.0.0.0/24 is subnetted, 1 subnets

D EX    2.2.2.0 [170/2474496] via 13.1.1.1, 00:00:35, Serial1/2

     3.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C       3.3.3.0/24 is directly connected, Loopback0

D       3.0.0.0/8 is a summary, 00:08:15, Null0

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

C       13.1.1.0/24 is directly connected, Serial1/2

D       13.0.0.0/8 is a summary, 00:08:15, Null0

 

 

EIGRP重发布进ISIS

先在R2上查看路由表

R2#sh ip route

     2.0.0.0/24 is subnetted, 1 subnets

C       2.2.2.0 is directly connected, Loopback0

     12.0.0.0/24 is subnetted, 1 subnets

C       12.1.1.0 is directly connected, Serial1/0

i*L1 0.0.0.0/0 [115/10] via 12.1.1.1, Serial1/0

 

在R1上进行重发布

R1(config)#router isis

R1(config-router)#redistribute eigrp 1(这里的1表示的是区域号，如果后面没带参数，默认的是level-2的路由重发布进ISIS区域)

 

R2#sh ip route

     2.0.0.0/24 is subnetted, 1 subnets

C       2.2.2.0 is directly connected, Loopback0

i L2 3.0.0.0/8 [115/10] via 12.1.1.1, Serial1/0

     12.0.0.0/24 is subnetted, 1 subnets

C       12.1.1.0 is directly connected, Serial1/0

     13.0.0.0/24 is subnetted, 1 subnets

i L2    13.1.1.0 [115/10] via 12.1.1.1, Serial1/0

i*L1 0.0.0.0/0 [115/10] via 12.1.1.1, Serial1/0

可以看到已经学习到EIGRP的重发布路由，并且是level-2的路由

 

R3#ping 2.2.2.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 12/33/52 ms

 

总结：

ISIS重发布进EIGRP需要看清楚当前路由器有没有level-2的路由，否则需要进行手工指定，并且还需要手工指定K值

EIGRP重发布进ISIS就比较简单，默认上以level-2的路由重发布进ISIS区域

 

isis区域中level-1和level-2的区别在于：

level-1相当于ospf区域的stub区域

level-2相当于ospf区域的area0qyu