BGP的水平分隔
A:
Router(config)#host A
A(config)#int lo0
A(config-if)#ip addr 192.168.10.1 255.255.255.0
A(config-if)#no shut
A(config)#int s1/0
A(config-if)#ip addr 202.110.100.1 255.255.255.0
A(config-if)#encap hdlc
A(config-if)#clock rate 56000
A(config-if)#no shut
A(config)#router bgp 64500
A(config-router)#neighbor 202.110.100.2 remote-as 64500
A(config-router)#net 192.168.10.0
A(config-router)#net 202.110.100.0
B
:
Router(config)#host B
B(config)#int s1/0
B(config-if)#ip addr 202.110.100.2 255.255.255.0
B(config-if)#encap hdlc
B(config-if)#no shut
B(config-if)#exit
B(config-router)#router bgp 64500
B(config-router)#neighbor 202.110.100.1 remote-as 64500
B(config-router)#net 202.110.100.0
B(config)#int s1/1
B(config-if)#ip addr 202.110.101.1 255.255.255.0
B(config-if)#encap hdlc
B(config-if)#clock rate 56000
B(config-if)#no shut
B(config)#router bgp 64500
B(config-router)#neighbor 202.110.101.2 remote-as 64500
B(config-router)#neighbor 202.110.101.2 remote-as 64500
B(config-router)#net 202.110.101.0
R3
Router(config)#host R3
R3(config)#int s1/1
R3(config-if)#ip addr 202.110.101.2 255.255.255.0
R3(config-if)#encap hdlc
R3(config-if)#no shut
R3(config-if)#exit
*Apr 21 21:00:10.551: %LINK-3-UPDOWN: Interface Serial1/1, changed state to upbgp
*Apr 21 21:00:11.555: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1, changed state to up 64500
R3(config-router)#router bgp 64500
R3(config-router)#neighbor 202.110.101.1 remote-as 64500
R3(config-router)#net 202.110.101.0
试验结果：
R2
能学到
10
网段路由，
R3
学不到路由。
B#show ip ro
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 202.110.100.0/24 is directly connected, Serial1/0
C 202.110.101.0/24 is directly connected, Serial1/1
B 192.168.10.0/24 [200/0] via 202.110.100.1, 00:20:36
C.
r>i202.110.101.0 202.110.101.1 0 100 0 i
R3#show ip ro
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
B 202.110.100.0/24 [200/0] via 202.110.101.1, 00:00:25
C 202.110.101.0/24 is directly connected, Serial1/1
对于为什么是这种结果，在下一篇博文中将有详细解释。
本文转自shenleigang 51CTO博客，原文链接：
http://blog.51cto.com/shenleigang/152609
，如需转载请自行联系原作者
