用route-map篩選路由更新進而過濾路由

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二、在上一個實驗當中，我們用了distribute來篩選路由更新，那麼這次我們用route-map來做一下，前期工作還是一樣，配置各接口的IP和協定，并且在R2上做重分發，為了讓R1和R3學到明細路由我們要在R2上關閉RIP的自動彙總：

三、針對OSPF區域的配置步驟：

1、配置完IP和協定之後，先來看一下R1的路由表：

R1#sh ip route

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

     172.168.0.0/24 is subnetted, 4 subnets

C       172.168.0.0 is directly connected, Loopback0

C       172.168.1.0 is directly connected, Loopback0

C       172.168.2.0 is directly connected, Loopback0

C       172.168.3.0 is directly connected, Loopback0

     172.16.0.0/24 is subnetted, 1 subnets

C       172.16.255.0 is directly connected, Serial1/1

O E2 192.168.255.0/24 [110/200] via 172.16.255.2, 00:00:16, Serial1/1

O E2 192.168.0.0/24 [110/200] via 172.16.255.2, 00:00:16, Serial1/1

O E2 192.168.1.0/24 [110/200] via 172.16.255.2, 00:00:16, Serial1/1

O E2 192.168.2.0/24 [110/200] via 172.16.255.2, 00:00:16, Serial1/1

O E2 192.168.3.0/24 [110/200] via 172.16.255.2, 00:00:16, Serial1/1   (沒做過濾之前學到了5條O E2 型路由)

2、再來看一下R3的路由表：

R3#sh ip route

     172.168.0.0/16 is variably subnetted, 4 subnets, 2 masks

R       172.168.1.0/24 [120/10] via 192.168.255.2, 00:00:24, Serial1/0

R       172.168.0.1/32 [120/10] via 192.168.255.2, 00:00:24, Serial1/0

R       172.168.2.0/24 [120/10] via 192.168.255.2, 00:00:24, Serial1/0

R       172.168.3.0/24 [120/10] via 192.168.255.2, 00:00:24, Serial1/0

R       172.16.255.0 [120/10] via 192.168.255.2, 00:00:24, Serial1/0     (沒做過濾之前學到了5條R型路由)  

C    192.168.255.0/24 is directly connected, Serial1/0

C    192.168.0.0/24 is directly connected, Loopback0

C    192.168.1.0/24 is directly connected, Loopback0

C    192.168.2.0/24 is directly connected, Loopback0

C    192.168.3.0/24 is directly connected, Loopback0

3、那麼我在R2做上針對rip重分發到ospf區域的通路控制清單，并且在route-map上調用，然後再引用route-map對重分發的路由進行過濾。

R2(config)#access-list 1 deny 192.168.2.0 0.0.0.255

R2(config)#access-list 1 deny 192.168.3.0 0.0.0.255

R2(config)#access-list 1 permit any

R2(config)#route-map rip-ospf permit 1 (建立rip到ospf 區域的route-map)

R2(config-route-map)#match ip address 1(比對通路控制清單1)

R2(config)#router ospf 1

R2(config-router)#redistribute rip route-map rip-ospf metric 200 subnets(引用route-map對重分發的路由進行過濾)

4、現在再看一下R1上的路由表：

R1#sho ip route

O E2 192.168.255.0/24 [110/200] via 172.16.255.2, 00:00:11, Serial1/1

O E2 192.168.0.0/24 [110/200] via 172.16.255.2, 00:00:10, Serial1/1

O E2 192.168.1.0/24 [110/200] via 172.16.255.2, 00:00:10, Serial1/1 (現在隻學到了3條)

四、針對OSPF區域的配置步驟

1、上一個步驟已經看到了R3的路由表，全部路由都學到了，那麼我現在還是要在R2上建立access-list，并在route-map上調用，然後再引用route-map對重分發的路由進行過濾。

R2(config)#access-list 2 deny 172.168.0.0 0.0.0.255

R2(config)#access-list 2 deny 172.168.1.0 0.0.0.255

R2(config)#access-list 2 permit any

R2(config)#route-map ospf-rip permit 2 (建立ospf到rip 區域的route-map)

R2(config-route-map)#match ip address 2(比對通路控制清單2)

R2(config)#router rip

R2(config-router)#redistribute ospf 1 route-map ospf-rip metric 10 (引用route-map對重分發的路由進行過濾)

     172.168.0.0/24 is subnetted, 2 subnets

R       172.168.2.0 [120/10] via 192.168.255.2, 00:00:11, Serial1/0

R       172.168.3.0 [120/10] via 192.168.255.2, 00:00:11, Serial1/0

R       172.16.255.0 [120/10] via 192.168.255.2, 00:00:11, Serial1/0  (隻學到了三條)

3、呵呵，現在變成隻能學到三條RIP那邊過來的路由，開始我很郁悶啊，這一步我一直clear ip route * ，但是卻一直還是5條R，檢查配置實在找不出原因，想想，我後來隻有把配置導出來，然後重新開機模拟器，再把配置導進去。後來就隻能學到這三條了，果然真是模拟器的原因。糾結啊。現在我們用route-map也能達到目的，或者用distribute-list 對路由更新篩選目的。不過用distribute-list步驟要少一點。不過沒關系。多一個方法，多一條路。現實生活和工作中何嘗不是呢？懂比不懂要好。

 本文轉自wxs-163 51CTO部落格，原文連結:

 http://blog.51cto.com/supercisco/255546