ccnp课程：简单路由重分发和ASBR汇总配置和验证

 

r1:
in e1/1
ip add 192.168.6.2 255.255.255.0
no sh
in e1/0
ip add 192.168.1.1 255.255.255.0
no sh
router ospf 1
net 192.168.6.2 0.0.0.0 a 0
net 192.168.1.1 0.0.0.0 a 0
r2:
in e1/2
ip add 192.168.5.2 255.255.255.0
no sh
in e1/1
ip add 192.168.2.1 255.255.255.0
no sh
router ospf 1
net 192.168.5.2 0.0.0.0 a 0
net 192.168.2.1 0.0.0.0 a 0
r3:
in e1/1
ip add 192.168.1.2 255.255.255.0
no sh
in e1/2
ip add 192.168.2.2 255.255.255.0
no sh
in e1/3
ip add 192.168.3.1 255.255.255.0
no sh
in e1/4
ip add 192.168.4.1 255.255.255.0
no sh
router ospf 1
net 192.168.1.2 0.0.0.0 a 0
net 192.168.2.2 0.0.0.0 a 0
net 192.168.3.1 0.0.0.0 a 1
net 192.168.4.1 0.0.0.0 a 1
r4:
in e1/1
ip add 192.168.3.2 255.255.255.0
no sh
ip ospf 1 a 1
r5:
in e1/1
ip add 192.168.4.2 255.255.255.0
no sh
ip opsf 1 a 1
r6:
in e1/0
ip add 192.168.6.1 255.255.255.0
no sh
in e1/1
ip add 192.168.5.1 255.255.255.0
in loop 1
ip add 172.16.0.1 255.255.255.0
in loop 2
ip add 172.16.1.1 255.255.255.0
in loop 3
ip add 172.16.2.1 255.255.255.0
in loop 4
ip add 172.16.3.1 255.255.255.0
router ospf 1
net 192.168.6.1 0.0.0.0 a 0
net 192.168.5.1 0.0.0.0 a 0
redistribute eigrp 100 subnets
router eigrp 100
net 172.16.0.0 0.0.255.255
redestribute ospf 1 metric 10000 100 255 1 1500

验证命令：
show ip ro
show ip pro
show ip ospf data
show ip ospf nei
show ip rout ospf

先看看在执行重分发之前r4的路由表：
r4#show ip ro
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

O    192.168.4.0/24 [110/20] via 192.168.3.1, 00:07:46, Ethernet1/1
O IA 192.168.5.0/24 [110/30] via 192.168.3.1, 00:05:30, Ethernet1/1
O IA 192.168.6.0/24 [110/30] via 192.168.3.1, 00:06:11, Ethernet1/1
O IA 192.168.1.0/24 [110/20] via 192.168.3.1, 00:07:46, Ethernet1/1
O IA 192.168.2.0/24 [110/20] via 192.168.3.1, 00:07:46, Ethernet1/1
C    192.168.3.0/24 is directly connected, Ethernet1/1
执行重分发后r4的路由表：
r4#  http://www.luyouqiwang.com/14471/   show ip route ospf
     172.16.0.0/24 is subnetted, 4 subnets
O E2    172.16.0.0 [110/20] via 192.168.3.1, 00:23:12, Ethernet1/1
O E2    172.16.1.0 [110/20] via 192.168.3.1, 00:23:12, Ethernet1/1
O E2    172.16.2.0 [110/20] via 192.168.3.1, 00:23:12, Ethernet1/1
O E2    172.16.3.0 [110/20] via 192.168.3.1, 00:23:12, Ethernet1/1
O    192.168.4.0/24 [110/20] via 192.168.3.1, 00:30:58, Ethernet1/1
O IA 192.168.5.0/24 [110/30] via 192.168.3.1, 00:28:42, Ethernet1/1
O IA 192.168.6.0/24 [110/30] via 192.168.3.1, 00:29:23, Ethernet1/1
O IA 192.168.1.0/24 [110/20] via 192.168.3.1, 00:30:58, Ethernet1/1
O IA 192.168.2.0/24 [110/20] via 192.168.3.1, 00:30:58, Ethernet1/1
是否发现路由条目有一些不同？出现了4条在eigrp中配置的172.16网段的路由条目，而且在O后面标注了E2，这表明这是一条2类外部

路由，ospf默认从外部重分发的路由为2类外部路由。当然还有1类外部路由，至于其中有什么不同我也不细讲了。
解释一下重分发的配置：
要将eigrp路由重分发到ospf，那么我们应该进入ospf路由配置模式。在路由配置模式下，打出这条命令redistribute eigrp 100

subnets,这条命令将eigrp 100的路由重分发到ospf。注意如果不打上subnets是不会重分发子网的。
要将ospf重分发到eigrp，我们应进入eigrp路由配置模式，在路由配置模式下，打出这条命令redestribute ospf 1 metric 10000

100 255 1 1500，重点是metric后面的5个值，这5个值就是eigrp的5个k值，依次为带宽，延迟，可靠度，负载和MTU值。从别的路由

重分发到ospf的2类外部路由默认度量值为20，而重分发到eigrp如果没有打上metric后的5个k值，那么度量值为无穷大，而无穷大代

表路由不可达，所以必须打上这几个值。

照例讲一下在ASBR上的路由汇总，昨天我讲过在ABR上进行汇总。大家对比一下，到现在我已经讲过3种汇总方法了，大家总结一下，

看看有什么区别。

很简单，一条命令搞定。

r6：
router ospf 1
summary-address 172.16.0.0 255.255.252.0
再看看r4汇总后的路由表吧。
r4#show ip rout ospf
     172.16.0.0/22 is subnetted, 1 subnets
O E2    172.16.0.0 [110/20] via 192.168.3.1, 00:03:19, Ethernet1/1
O    192.168.4.0/24 [110/20] via 192.168.3.1, 00:49:26, Ethernet1/1
O IA 192.168.5.0/24 [110/30] via 192.168.3.1, 00:47:10, Ethernet1/1
O IA 192.168.6.0/24 [110/30] via 192.168.3.1, 00:47:51, Ethernet1/1
O IA 192.168.1.0/24 [110/20] via 192.168.3.1, 00:49:26, Ethernet1/1
O IA 192.168.2.0/24 [110/20] via 192.168.3.1, 00:49:26, Ethernet1/1
4条外部路由被汇总为1条172.16.0.0了。