配置

r1

建立EBGP对等体

[r1]bgp 100
[r1-bgp]router-id 1.1.1.1
[r1-bgp]peer 12.0.0.2 as-number 200

[r1]ip route-static 2.2.2.2 32 12.0.0.2

[r1]bgp 100
[r1-bgp]router-id 1.1.1.1
[r1-bgp]peer 2.2.2.2 as-number 200
[r1-bgp]peer 2.2.2.2 connect-interface LoopBack 0 
[r1-bgp]peer 2.2.2.2 ebgp-max-hop 2

发布路由1.1.1.1

[r1]bgp 100
[r1-bgp]network 1.1.1.1 32

r2

建立EBGP对等体

[r2]bgp 200
[r2-bgp]router-id 2.2.2.2
[r2-bgp]peer 12.0.0.1 as-number 100

[r2]ip route-static 2.2.2.2 32 12.0.0.1 

[r2]bgp 200
[r2-bgp]router-id 2.2.2.2
[r2-bgp]peer 1.1.1.1 as-number 100
[r2-bgp]peer 1.1.1.1 connect-interface LoopBack 0
[r2-bgp]peer 1.1.1.1 ebgp-max-hop 2

ospf

[r2]ospf 1 router-id 10.0.2.2
[r2-ospf-1]a 0
[r2-ospf-1]network 2.2.2.2 0.0.0.0
[r2-ospf-1]network 23.0.0.2 0.0.0.0

建立IBGP对等体

[r2]bgp 200
[r2-bgp]router-id 2.2.2.2
[r2-bgp]peer 3.3.3.3 as-number 200
[r2-bgp]peer 3.3.3.3 connect-interface LoopBack 0

改下一跳解决无法递归

[r2-bgp]peer 3.3.3.3 next-hop-local

建立全连的IBGP对等体  
[r2-bgp]peer 4.4.4.4 as-number 200
[r2-bgp]peer 4.4.4.4 connect-interface LoopBack 0

更改下一跳

[r2]bgp 200
[r2-bgp]peer 4.4.4.4 next-hop-local

r3

ospf

[r3]ospf 1 router-id 10.0.3.3
[r3-ospf-1]a 0
[r3-ospf-1]network 3.3.3.3 0.0.0.0
[r3-ospf-1]network 23.0.0.3 0.0.0.0
[r3-ospf-1]network 34.0.0.3 0.0.0.0

建立IBGP对等体

[r3]bgp 200
[r3-bgp]router-id 3.3.3.3
[r3-bgp]peer 2.2.2.2 as-number 200
[r3-bgp]peer 2.2.2.2 connect-interface LoopBack 0

r4

ospf

[r4]ospf 1 router-id 10.0.4.4
[r4-ospf-1]a 0
[r4-ospf-1]network 4.4.4.4 0.0.0.0
[r4-ospf-1]network 34.0.0.4 0.0.0.0

IBGP对等体

[r4]bgp 200
[r4-bgp]router-id 4.4.4.4
[r4-bgp]peer 3.3.3.3 as-number 200
[r4-bgp]peer 3.3.3.3 connect-interface LoopBack 0

建立全连的IBGP对等体  
[r4]bgp 200   
[r4-bgp]peer 2.2.2.2 as-number 200   
[r4-bgp]peer 2.2.2.2 connect-interface LoopBack 0

更改下一跳

[r4]bgp 200
[r4-bgp]peer 2.2.2.2 next-hop-local
[r4-bgp]peer 3.3.3.3 next-hop-local

r5

发布路由5.5.5.5
[r5-bgp]network 5.5.5.5 32

发布路由10.1.1.1 删除5.5.5.5
[r5-bgp]undo network 5.5.5.5 
[r5-bgp]network 10.1.1.1 24