3.3 路由同步及路由黑洞

1.R1配置OSPF

[R4]ospf 1 router-id 1.1.1.1
[R4-ospf-1]area 0
[R4-ospf-1-area-0.0.0.0]network 1.1.1.1 0.0.0.0
[R4-ospf-1-area-0.0.0.0]network 12.1.1.0 0.255.255.255

2.R2配置OSPF

[R2]ospf 1 router-id 2.2.2.2
[R2-ospf-1]area 0
[R2-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0
[R2-ospf-1-area-0.0.0.0]network 12.1.1.0 0.255.255.255
[R2-ospf-1-area-0.0.0.0]network 23.1.1.0 0.255.255.255

3.R3配置OSPF

[R3]ospf 1 router-id 3.3.3.3
[R3-ospf-1]area 0
[R3-ospf-1-area-0.0.0.0]network 3.3.3.3 0.0.0.0
[R3-ospf-1-area-0.0.0.0]network 23.1.1.0 0.255.255.255

4.R1配置IBGP

[R1]bgp 123
[R1-bgp]router-id 1.1.1.1
[R1-bgp]peer 3.3.3.3 as-number 123
[R1-bgp]peer 3.3.3.3 connect-interface LoopBack 0

5.R3配置IBGP和EBGP

[R3]bgp 123
[R3-bgp]router-id 3.3.3.3
[R3-bgp]peer 1.1.1.1 as-number 123
[R3-bgp]peer 1.1.1.1 connect-interface LoopBack 0
[R3-bgp]peer 1.1.1.1 next-hop-local
[R3-bgp]peer 34.1.1.4 as-number 400

6.R4配置EBGP

[R4]bgp 400
[R4-bgp]router-id 4.4.4.4
[R4-bgp]peer 34.1.1.3 as-number 123
[R4-bgp]network 4.4.4.4 32

7.R1的BGP宣告11.11.11.11/32

[R1-bgp]network 11.11.11.11 32

8.查看R3的BGP路由表，无11.11.11.11/32路由，产生路由黑洞。

[R3]display bgp routing-table
 *>   4.4.4.4/32         34.1.1.4        0                     0      400i

9.R1、R2、R3配置IBGP，R4的BGP宣告4.4.4.4/32

[R1]bgp 123
[R1-bgp]peer 2.2.2.2 as-number 123
[R1-bgp]peer 2.2.2.2 connect-interface LoopBack 0

[R2]bgp 123
[R2-bgp]router-id 2.2.2.2
[R2-bgp]peer 1.1.1.1 as-number 123
[R2-bgp]peer 1.1.1.1 connect-interface LoopBack 0
[R2-bgp]peer 3.3.3.3 as-number 123
[R2-bgp]peer 3.3.3.3 connect-interface LoopBack 0

[R3]bgp 123
[R3-bgp]peer 2.2.2.2 as-number 123
[R3-bgp]peer 2.2.2.2 connect-interface LoopBack 0
[R3-bgp]peer 2.2.2.2 next-hop-local
[R3-bgp]peer 1.1.1.1 next-hop-local
[R4]bgp 400
[R4-bgp]network 4.4.4.4 32

10.查看R1、R4的BGP路由表

<R1>display bgp routing-table
*>i  4.4.4.4/32         3.3.3.3         0          100        0      400i
 *>   11.11.11.11/32     0.0.0.0         0                     0      i

<R4>display bgp routing-table

 *>   4.4.4.4/32         0.0.0.0         0                     0      i
 *>   11.11.11.11/32     34.1.1.3                              0      123i