实验拓扑图：
IOU1的配置
Configure terminal
Interface ethernet 0/0
Duplex full
Ip address 10.0.10.1 255.255.255.0
No shutdown
Exit
Interface loopback 0
Ip address 1.1.1.1 255.255.255.0
No shutdown
Exit
Interface loopback 1
Ip address 2.2.2.2 255.255.255.0
No shutdown
Exit
BGP的配置
Router bgp 100
Neighbor 10.0.10.2 remote-as 300
Network 1.1.1.0 mask 255.255.255.0
Network 2.2.2.0 mask 255.255.255.0
Exit
IOU2的配置
Configure terminal
Interface ethernet 0/0
Duplex full
Ip address 10.0.40.1 255.255.255.0
No shutdown
Exit
Interface loopback 0
Ip address 1.1.1.1 255.255.255.0
No shutdown
Exit
Interface loopback 1
Ip address 2.2.2.2 255.255.255.0
No shutdown
Exit
BGP的配置
Router bgp 200
Neighbor 10.0.40.2 remote-as 300
Network 1.1.1.0 mask 255.255.255.0
Network 2.2.2.0 mask 255.255.255.0
Exit
IOU3的配置
Configure terminal
Interface ethernet 0/0
Duplex full
Ip address 10.0.10.2 255.255.255.0
No shutdown
Exit
Interface ethernet 0/1
Duplex full
Ip address 10.0.20.1 255.255.255.0
No shutdown
Exit
Interface loopback 0
Ip address 3.3.3.3 255.255.255.0
No shutdown
Exit
OSPF配置
Router ospf 1
Router-id 3.3.3.3
Network 3.3.3.0 0.0.0.255 area 0
Network 10.0.20.0 0.0.0.255 area 0
Exit
BGP的配置
Router bgp 300
Neighbor 1.1.1.1 remote-as 100
Neighbor 2.2.2.2 remote-as 100
Neighbor 4.4.4.4 remote-as 300
Neighbor 5.5.5.5 remote-as 300
Neighbor 10.0.10.1 remote-as 100
Neighbor 4.4.4.4 update-source loopback 0
Neighbor 5.5.5.5 update-source loopback 0
Network 3.3.3.0 mask 255.255.255.0
Exit
IOU4的配置
Configure terminal
Interface ethernet 0/0
Duplex full
Ip address 10.0.40.2 255.255.255.0
No shutdown
Exit
Interface ethernet 0/1
Duplex full
Ip address 10.0.30.1 255.255.255.0
No shutdown
Exit
Interface loopback 0
Ip address 4.4.4.4 255.255.255.0
No shutdown
Exit
OSPF的配置
Router ospf 1
Router-id 4.4.4.4
Network 4.4.4.0 0.0.0.255 area 0
Network 10.0.30.0 0.0.0.255 area 0
Exit
BGP的配置
Router bgp 300
Neighbor 3.3.3.3 remote-as 300
Neighbor 5.5.5.5 remote-as 300
Neighbor 10.0.40.1 remote-as 200
Neighbor 3.3.3.3 update-source loopback 0
Neighbor 5.5.5.5 update-source loopback 0
Neighbor 5.5.5.5 next-hop-self
Network 4.4.4.0 mask 255.255.255.0
Exit
IOU5的配置
Configure terminal
Interface ethernet 0/0
Duplex full
Ip address 10.0.20.2 255.255.255.0
No shutdown
Exit
Interface ethernet 0/1
Duplex full
Ip address 10.0.30.2 255.255.255.0
No shutdown
Exit
Interface loopback 0
Ip address 5.5.5.5 255.255.255.0
No shutdown
Exit
OSPF的配置
Router ospf 1
Router-id 5.5.5.5
Network 5.5.5.0 0.0.0.255 area 0
Network 10.0.20.0 0.0.0.255 area 0
Network 10.0.30.0 0.0.0.255 area 0
Exit
BGP的配置
Router bgp 300
Neighbor 3.3.3.3 remote-as 300
Neighbor 4.4.4.4 remote-as 300
Neighbor 3.3.3.3 update-source loopback 0
Neighbor 4.4.4.4 update-source loopback 0
Network 5.5.5.0 mask 255.255.255.0
Exit
