详细解析配置BGP负载共享

　　R101的BGP表中显示所以去往Internet的流量都通过链R101-R103.

R101#sh ip bgp BGP table version is 6, local router ID is 192.168.12.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path * i0.0.0.0 192.168.12.2 100 0 10 i *> 10.10.13.3 0 10 i *> 10.10.34.0/24 10.10.13.3 0 0 10 i * i 192.168.12.2 100 0 10 i * i192.168.11.0 192.168.12.2 0 100 0 i *> 0.0.0.0 0 32768 i * i192.168.12.0 192.168.12.2 0 100 0 i *> 0.0.0.0 0 32768 i R101#sh ip ro Gateway of last resort is 10.10.13.3 to network 0.0.0.0 C 192.168.12.0/24 is directly connected, FastEthernet0/0 C 192.168.11.0/24 is directly connected, FastEthernet0/0 10.0.0.0/24 is subnetted, 2 subnets C 10.10.13.0 is directly connected, Serial1/1 B 10.10.34.0 [20/0] via 10.10.13.3, 00:02:39 B* 0.0.0.0/0 [20/0] via 10.10.13.3, 00:13:01

　　R102的BGP表中显示按照路由策略所以去往AS10的流量都通过R102-R104.

R102#sh ip bgp BGP table version is 5, local router ID is 192.168.12.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0 10.10.24.4 0 10 i * i 192.168.12.1 100 0 10 i * i10.10.34.0/24 192.168.12.1 0 100 0 10 i *> 10.10.24.4 0 10 i * i192.168.11.0 192.168.12.1 0 100 0 i *> 0.0.0.0 0 32768 i * i192.168.12.0 192.168.12.1 0 100 0 i *> 0.0.0.0 0 32768 i R102#sh ip ro Gateway of last resort is 10.10.24.4 to network 0.0.0.0 C 192.168.12.0/24 is directly connected, FastEthernet0/0 C 192.168.11.0/24 is directly connected, FastEthernet0/0 10.0.0.0/24 is subnetted, 2 subnets C 10.10.24.0 is directly connected, Serial1/2 B 10.10.34.0 [20/0] via 10.10.24.4, 00:04:12 B* 0.0.0.0/0 [20/0] via 10.10.24.4, 00:12:08

　　验证从AS10进入AS11的流量。去往网络192.168.11.0的流量走链路R103-R101，去往网络162.168.12.0的流量走链路R104-R102.

R103# sh ip bgp BGP table version is 5, local router ID is 10.10.34.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 10.10.34.0/24 0.0.0.0 0 32768 i *> 192.168.11.0 10.10.13.1 0 0 11 i *>i192.168.12.0 10.10.34.4 0 100 0 11 i * 10.10.13.1 0 0 11 11 11 11 i R103#sh ip ro Gateway of last resort is not set B 192.168.12.0/24 [200/0] via 10.10.34.4, 00:49:14 B 192.168.11.0/24 [20/0] via 10.10.13.1, 00:52:36 10.0.0.0/24 is subnetted, 2 subnets C 10.10.13.0 is directly connected, Serial1/0 C 10.10.34.0 is directly connected, FastEthernet0/0

　　在R104上情况相同。

　　当R101-R103的链路失效后，R102-R104成为其备分链路

R103(config)#int s1/0 R103(config-if)#sh R101#sh ip bgp BGP table version is 8, local router ID is 192.168.12.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *>i0.0.0.0 192.168.12.2 100 0 10 i *>i10.10.34.0/24 192.168.12.2 100 0 10 i * i192.168.11.0 192.168.12.2 0 100 0 i *> 0.0.0.0 0 32768 i * i192.168.12.0 192.168.12.2 0 100 0 i *> 0.0.0.0 0 32768 i R101#sh ip ro Gateway of last resort is 192.168.12.2 to network 0.0.0.0 C 192.168.12.0/24 is directly connected, FastEthernet0/0 C 192.168.11.0/24 is directly connected, FastEthernet0/0 10.0.0.0/24 is subnetted, 1 subnets B 10.10.34.0 [200/0] via 192.168.12.2, 00:01:42 B* 0.0.0.0/0 [200/0] via 192.168.12.2, 00:01:42 R103#sh ip bgp BGP table version is 7, local router ID is 10.10.34.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 10.10.34.0/24 0.0.0.0 0 32768 i *>i192.168.11.0 10.10.34.4 0 100 0 11 11 11 11 i *>i192.168.12.0 10.10.34.4 0 100 0 11 i R103#sh ip ro Gateway of last resort is not set B 192.168.12.0/24 [200/0] via 10.10.34.4, 01:09:47 B 192.168.11.0/24 [200/0] via 10.10.34.4, 00:14:08 10.0.0.0/24 is subnetted, 1 subnets C 10.10.34.0 is directly connected, FastEthernet0/0