基于回环口的BGP配置

拓扑图

 

实验过程

 

1.       R1的预配置

Router>en Router#config t Enter configuration commands, one per line.  End with CNTL/Z. Router(config)#no ip domain-lookup Router(config)#line console 0 Router(config-line)#no exec-timeout Router(config-line)#loggin syn Router(config-line)#exit Router(config)#host R1 R1(config)#int lo0 R1(config-if)#ip add 172.16.0.1 255.255.255.0 R1(config-if)#int lo1 R1(config-if)#ip add 172.16.1.1 255.255.255.0 R1(config-if)#int f0/0 R1(config-if)#no shut R1(config-if)#ip add 172.16.255.1 255.255.255.252 R1(config-if)#exit R1(config)# R1(config)#router rip R1(config-router)#version 2 R1(config-router)#no auto R1(config-router)#net  172.16.0.0 R1(config-router)#end

2.       R2的预配置

Router>en Router#config t Enter configuration commands, one per line.  End with CNTL/Z. Router(config)#no ip domain-lookup Router(config)#line console 0 Router(config-line)#no exec-timeout Router(config-line)#loggin syn Router(config-line)#exit Router(config)#host R2 R2(config)#int lo0 R2(config-if)#ip add 172.16.16.1 255.255.255.0 R2(config-if)#int f0/0 R2(config-if)#no shut R2(config-if)#ip add 172.16.255.2 255.255.255.252 R2(config-if)#int s1/0 R2(config-if)#no shut R2(config-if)#ip add 10.1.255.1 255.255.255.252 R2(config-if)#exit R2(config)# R2(config)#router rip R2(config-router)#version 2 R2(config-router)#no auto R2(config-router)#net 172.16.0.0 R2(config-router)#exit R2(config)#ip route 192.168.0.0 255.255.255.0 10.1.255.2

3.       R3的预配置

Router>en Router#config t Enter configuration commands, one per line.  End with CNTL/Z. Router(config)#no ip domain-lookup Router(config)#line console 0 Router(config-line)#no exec-timeout Router(config-line)#loggin syn Router(config-line)#exit Router(config)#host R3 R3(config)#int lo0 R3(config-if)#ip add 192.168.0.1 255.255.255.0 R3(config-if)#int lo1 R3(config-if)#ip add 192.168.1.1 255.255.255.0 R3(config-if)#int s1/0 R3(config-if)#no shut R3(config-if)#ip add 10.1.255.2 255.255.255.252 R3(config-if)#exit R3(config)#ip route 172.16.16.0 255.255.255.0 10.1.255.1

4.       配置R1的BGP

R1(config)#router bgp 100 R1(config-router)#nei 172.16.16.1 remote-as 100 R1(config-router)#nei 172.16.16.1 update-source lo0  //指定更新源为回环口 R1(config-router)#net 172.16.0.0 mask 255.255.255.0 R1(config-router)#net 172.16.1.0 mask 255.255.255.0 R1(config-router)#net 172.16.255.0 mask 255.255.255.252 R1(config-router)#end

5.       配置R2的BGP

R2(config)#router bgp 100 R2(config-router)#nei 172.16.0.1 remote-as 100 R2(config-router)#nei 172.16.0.1 update-source lo0 R2(config-router)#nei 172.16.0.1 next-hop-self  //指定下一跳为自己 R2(config-router)#nei 192.168.0.1 remote-as 200 R2(config-router)#nei 192.168.0.1 update-source lo0 R2(config-router)#nei 192.168.0.1 next-hop-self R2(config-router)#nei 192.168.0.1 ebgp-m 2  //打开ebgp多跳 R2(config-router)#net 172.16.255.0 mask 255.255.255.252 R2(config-router)#net 10.1.255.0 mask 255.255.255.252 R2(config-router)#net 172.16.16.0 mask 255.255.255.0 R2(config-router)#end

6.       配置R3的BGP

R3(config)#router bgp 200 R3(config-router)#nei 172.16.16.1 remote-as 100 R3(config-router)#nei 172.16.16.1 update-source lo0 R3(config-router)#nei 172.16.16.1 ebgp-m 2 R3(config-router)#net 192.168.0.0 mask 255.255.255.0 R3(config-router)#net 192.168.1.0 mask 255.255.255.0 R3(config-router)#net 10.1.255.0 mask 255.255.255.252 R3(config-router)#end

7.       查看BGP信息

R1#show ip bgp BGP table version is 9, local router ID is 172.16.1.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,               r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete      Network          Next Hop            Metric LocPrf Weight Path *>i10.1.255.0/30    172.16.16.1              0    100      0 i *> 172.16.0.0/24    0.0.0.0                  0         32768 i *> 172.16.1.0/24    0.0.0.0                  0         32768 i r>i172.16.16.0/24   172.16.16.1              0    100      0 i * i172.16.255.0/30  172.16.16.1              0    100      0 i *>                  0.0.0.0               0         32768 i *>i192.168.0.0      172.16.16.1              0    100      0 200 i *>i192.168.1.0      172.16.16.1              0    100      0 200 i

8.       查看路由表

R1#show 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        172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks C       172.16.255.0/30 is directly connected, FastEthernet0/0 R       172.16.16.0/24 [120/1] via 172.16.255.2, 00:00:20, FastEthernet0/0 C       172.16.0.0/24 is directly connected, Loopback0 C       172.16.1.0/24 is directly connected, Loopback1      10.0.0.0/30 is subnetted, 1 subnets B       10.1.255.0 [200/0] via 172.16.16.1, 00:08:42 B    192.168.0.0/24 [200/0] via 172.16.16.1, 00:08:42 B    192.168.1.0/24 [200/0] via 172.16.16.1, 00:08:42

9.       测试连通性

R1#ping 192.168.0.1 source lo0   Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds: Packet sent with a source address of 172.16.0.1 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 44/69/100 ms R1#ping 192.168.0.1 source lo1   Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds: Packet sent with a source address of 172.16.1.1 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 36/49/68 ms