BGP联邦实验

 今天做一个联邦的实验，

BGP联邦的主要用途是减少IBGP关系的数量，也使网络的配置更加简单。

 

R1#show run | s bgp
router bgp 64512
 no synchronization
 bgp router-id 1.1.1.1
 bgp log-neighbor-changes
 bgp confederation identifier 200
 bgp confederation peers 64513
 neighbor 3.3.3.3 remote-as 64512
 neighbor 3.3.3.3 update-source Loopback0
 neighbor 3.3.3.3 next-hop-self
 neighbor 10.1.1.10 remote-as 100
 neighbor 10.1.1.10 next-hop-self
 neighbor 12.1.1.2 remote-as 64513
 neighbor 12.1.1.2 next-hop-self
 no auto-summary

 

 

R0#show run | s bgp
router bgp 100
 no synchronization
 bgp log-neighbor-changes
 network 100.1.1.0 mask 255.255.255.0
 network 100.1.1.1 mask 255.255.255.255
 neighbor 10.1.1.1 remote-as 200
 neighbor 20.1.1.2 remote-as 200
 no auto-summary

 

 

R2#show run | s bgp
router bgp 64513
 no synchronization
 bgp router-id 3.3.3.3
 bgp log-neighbor-changes
 bgp confederation identifier 200
 bgp confederation peers 64512
 network 2.2.2.2 mask 255.255.255.255
 network 24.1.1.0 mask 255.255.255.0
 neighbor 4.4.4.4 remote-as 64513
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 next-hop-self
 neighbor 12.1.1.1 remote-as 64512
 neighbor 12.1.1.1 next-hop-self
 neighbor 20.1.1.20 remote-as 100
 no auto-summary

 

 

R3#show run | s bgp
router bgp 64512
 no synchronization
 bgp router-id 3.3.3.3
 bgp log-neighbor-changes
 network 3.3.3.0 mask 255.255.255.0
 network 3.3.3.3 mask 255.255.255.255
 network 13.1.1.0 mask 255.255.255.0
 neighbor 1.1.1.1 remote-as 64512
 neighbor 1.1.1.1 update-source Loopback0
 no auto-summary

 

 

R4#show run | s bgp
router bgp 64513
 no synchronization
 bgp log-neighbor-changes
 network 4.4.4.4 mask 255.255.255.255
 network 24.1.1.0 mask 255.255.255.0
 neighbor 2.2.2.2 remote-as 64513
 neighbor 2.2.2.2 update-source Loopback0
 no auto-summary

 

配置过程中，有一点需要特别注意的，我们低层用的IGP是OSPF，在R1 和R2上注意不要把去往的R0 的接口network进来。如果network进来，可能会使我们的网络内部的拓扑泄漏出去。

考虑一下这种情况，R0也使用OSPF，network了10.1.1.0网段。R1和R2也network了10.1.1.0 这个网段，会怎么样？这样R0和R1 R2就会交换OSPF链路信息了。

因此在这种情况下，一般用静态路由去往另一个AS 。