编者按：本文介绍了边界路由与ISP电信网通网络进行负载共享的几种场景及相应的解决办法，具有相当的参考价值。
1.两台边界路由远程使用Loopback进行负载共享
该场景展示如何在多条（最大可有6条）等价链路上完成负载共享。该链路建立在本地AS中一台路由器和远程AS中另一台路由器之间是一个单宿主末端网络 BGP环境。
拓扑图如下：
配置如下：
RouterA
RA(config)#int s1/1
RA(config-if)#ip add 150.10.10.1 255.255.255.0
RA(config-if)#no sh
RA(config-if)#int s1/2
RA(config-if)#ip add 160.20.20.1 255.255.255.0
RA(config-if)#no sh
RA(config-if)#int lo0
RA(config-if)#ip add 1.1.1.1 255.255.255.0
RA(config)#router bgp 11
RA(config-router)#nei 2.2.2.2 remote-as 10
RA(config-router)#nei 2.2.2.2 update-source lo0
RA(config-router)#nei 2.2.2.2 ebgp-multihop
RA(config-router)#router eigrp 12
RA(config-router)#net 1.0.0.0
RA(config-router)#net 150.10.0.0
RA(config-router)#net 160.20.0.0
RA(config-router)#no auto-summary
RrouterB
RB(config)#int lo0
RB(config-if)#ip add 2.2.2.2 255.255.255.0
RB(config-if)#int s1/1
RB(config-if)#no ip route-cache
RB(config-if)#ip add 160.20.20.2 255.255.255.0
RB(config-if)#no sh
RB(config-if)#int s1/2
RB(config-if)#no ip route-cache
RB(config-if)#ip add 150.10.10.2 255.255.255.0
RB(config-if)#no sh
RB(config-if)#router bgp 10
RB(config-router)#nei 1.1.1.1 remote-as 11
RB(config-router)#nei 1.1.1.1 update-source lo0
RB(config-router)#nei 1.1.1.1 ebgp-multihop
RB(config-router)#router eigrp 12
RB(config-router)#net 2.0.0.0
RB(config-router)#net 150.10.0.0
RB(config-router)#net 160.20.0.0
RB(config-router)#no auto-summary
验证基于数据包（过程交换）的负载均衡：
RA#sh ip ro
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
2.0.0.0/24 is subnetted, 1 subnets
D 2.2.2.0 [90/2297856] via 150.10.10.2, 00:18:47, Serial1/1
[90/2297856] via 160.20.20.2, 00:18:47, Serial1/2
160.20.0.0/24 is subnetted, 1 subnets
C 160.20.20.0 is directly connected, Serial1/2
150.10.0.0/24 is subnetted, 1 subnets
C 150.10.10.0 is directly connected, Serial1/1
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RA#traceroute 2.2.2.2
Type escape sequence to abort.
Tracing the route to 2.2.2.2
1 150.10.10.2 36 msec
160.20.20.2 60 msec *
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