CCNP(BSCI)实验：配置BGP的路由过滤和默认路由

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starshomes 2020-09-27 10:04:08 ©著作权

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第一步：预配置 R1(config)#int lo0 R1(config-if)#ip add 1.1.1.1 255.255.255.0 R1(config-if)#int s2/1 R1(config-if)#ip add 12.0.0.1 255.255.255.0 R1(config-if)#no sh

R2(config)#int lo0 R2(config-if)#ip add 2.2.2.2 255.255.255.0 R2(config-if)#int s2/1 R2(config-if)#ip add 12.0.0.2 255.255.255.0 R2(config-if)#no sh R2(config-if)#int s2/2 R2(config-if)#ip add 23.0.0.2 255.255.255.0 R2(config-if)#no sh

R3(config)#int lo0 R3(config-if)#ip add 3.3.3.3 255.255.255.0 R3(config-if)#int s2/1 R3(config-if)#ip add 23.0.0.3 255.255.255.0 R3(config-if)#no sh R3(config-if)#int s2/2 R3(config-if)#ip add 34.0.0.3 255.255.255.0

第二步：配置BGP R1(config)#router bgp 100 R1(config-router)#nei 12.0.0.2 remote-as 200 R1(config-router)#net 1.1.1.0 mask 255.255.255.0

R2(config)#router bgp 200 R2(config-router)#nei 12.0.0.1 remote-as 100 R2(config-router)#nei 23.0.0.3 remote-as 300 R2(config-router)#net 2.2.1.0 mask 255.255.255.0 R2(config-router)#net 2.2.2.0 mask 255.255.255.0

R3(config)#router bgp 300 R3(config-router)#nei 23.0.0.2 remote-as 200 R3(config-router)#net 3.3.3.0 mask 255.255.255.0 第三步：分别查看R1和R3的bgp表 R2#sh ip bgp BGP table version is 5, local router ID is 2.2.2.2 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 *> 1.1.1.0/24 12.0.0.1 0 0 100 i *> 2.2.1.0/24 0.0.0.0 0 32768 i *> 2.2.2.0/24 0.0.0.0 0 32768 i *> 3.3.3.0/24 23.0.0.3 0 0 300 i

R3#sh ip bgp BGP table version is 5, local router ID is 3.3.3.3 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 *> 1.1.1.0/24 23.0.0.2 0 200 100 i *> 2.2.1.0/24 23.0.0.2 0 0 200 i *> 2.2.2.0/24 23.0.0.2 0 0 200 i *> 3.3.3.0/24 0.0.0.0 0 32768 i 路由过滤 第三步：我们对路由进行过滤 R2(config)#access-list 1 permit 2.2.0.0 0.0.255.255 //抓取2.2.0.0 路由

access-list 1 permit 2.2.0.0 0.0.255.255 access-list 10 deny 1.1.1.0 0.0.0.255 access-list 10 permit any //我们分别写了两个控制表，并用在了下列所示bgp 200中 //再一个请注意，acl最后一句是deny any的，不显示。 router bgp 200 ………………………… neighbor 12.0.0.1 distribute-list 10 in neighbor 12.0.0.1 distribute-list 1 out //这两句是配置命令，要写入R2 我们预计在R3 的bgp表中将没有1.1.1.0 在R1的bgp表中将没有3.3.3.0

R3#sh ip bgp BGP table version is 4, local router ID is 3.3.3.3 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 *> 2.2.1.0/24 23.0.0.2 0 0 200 i *> 2.2.2.0/24 23.0.0.2 0 0 200 i *> 3.3.3.0/24 0.0.0.0 0 32768 i

R1#sh ip bgp BGP table version is 4, local router ID is 1.1.1.1 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 *> 1.1.1.0/24 0.0.0.0 0 32768 i *> 2.2.1.0/24 12.0.0.2 0 0 200 i *> 2.2.2.0/24 12.0.0.2 0 0 200 i

第四步：我们又no掉一句neighbor 12.0.0.1 distribute-list 10 in 看看R3bgp表中有了1.1.1.0/24的路由 R3#sh ip bgp BGP table version is 5, local router ID is 3.3.3.3 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 *> 1.1.1.0/24 23.0.0.2 0 200 100 i *> 2.2.1.0/24 23.0.0.2 0 0 200 i *> 2.2.2.0/24 23.0.0.2 0 0 200 i *> 3.3.3.0/24 0.0.0.0 0 32768 i 默认路由 第五步：在R1上创建一个网络，并通过BGP通告出去 R1(config)#int lo 1 R1(config-if)#ip add 10.0.0.1 255.255.255.0

R1(config)#router bgp 100 R1(config-router)#net 10.0.0.0 mask 255.255.255.0

R2(config)#ip default-network 10.0.0.0 //把10.0.0.0作为默认网络 R2#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 12.0.0.1 to network 10.0.0.0

1.0.0.0/24 is subnetted, 1 subnets B 1.1.1.0 [20/0] via 12.0.0.1, 00:06:00 2.0.0.0/24 is subnetted, 2 subnets C 2.2.1.0 is directly connected, Loopback1 C 2.2.2.0 is directly connected, Loopback0 3.0.0.0/24 is subnetted, 1 subnets B 3.3.3.0 [20/0] via 23.0.0.3, 00:05:35 23.0.0.0/24 is subnetted, 1 subnets C 23.0.0.0 is directly connected, Serial2/2

10.0.0.0/24 is subnetted, 1 subnets B* 10.0.0.0 [20/0] via 12.0.0.1, 00:06:00 12.0.0.0/24 is subnetted, 1 subnets C 12.0.0.0 is directly connected, Serial2/1

第六步：测试 R1(config)#int lo 2 R1(config-if)#ip add 100.0.0.1 255.255.255.0

R2# ping 100.0.0.1

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 100.0.0.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 8/28/68 ms