BGP选路规则

配置地址，AS123使用ospf保证通讯，修改接口类型保证ospf学习环回20.0,30.0,100.0 地址时，是以24位掩码学习，R1，R2，R3都处于BGP边界，各自都需要宣告三者的私网环回

1，

R4ip ip-prefix aa permit 192.168.10.0 24

R4route-policy aa permit node 10

R4-route-policyif-match ip-prefix aa

R4-route-policyapply preferred-value 100

R4route-policy aa permit node 20

R4bgp 400

R4-bgppeer 42.1.1.2 route-policy aa import

R4-bgp

2，

R4ip ip-prefix bb permit 192.168.11.0 24

R4route-policy aa permit node 15

R4-route-policyif-match ip-prefix bb

R4-route-policyapply as-path 123 123 500 overwrite ---使用已出现的AS号

Warning: The AS-Path lists of routes to which this route-policy is applied will

be overwritten. Continue? Y/Ny

3，R2

Huaweiip ip-prefix aa permit 192.168.12.0 24

Huaweiroute-policy aa permit node 10

Huawei-route-policyif-match ip-prefix aa

Huawei-route-policyapply cost 200

Huaweiroute-policy aa permit node 20

Huaweibgp 123

Huawei-bgppeer 42.1.1.4 route-policy aa export

R3：

Huaweiip ip-prefix aa permit 192.168.12.0 24

Huaweiroute-policy aa permit node 10

Huawei-route-policyif-match ip-prefix aa

Huawei-route-policyapply cost 20

Huaweiroute-policy aa permit node 20

Huaweibgp 123

Huawei-bgppeer 43.1.1.4 route-policy aa export

4，5

Huaweiip ip-prefix aa permit 192.168.1.0 24

Huaweiip ip-prefix bb permit 192.168.2.0 24

Huaweiroute-policy aa permit node 10

Huawei-route-policyif-match ip-prefix aa

Huawei-route-policyapply local-preference 200

Huaweiroute-policy aa permit node 20

Huaweiroute-policy bb permit node 10

Huawei-route-policyif-match ip-prefix bb

Huawei-route-policyapply local-preference 200

Huaweiroute-policy bb permit node 20

Huaweibgp

Huaweibgp 123

Huawei-bgppeer 2.2.2.2 route-policy aa import

Huawei-bgppeer 3.3.3.3 route-policy bb import

Huawei-bgp

6，

Huaweibgp 123

Huawei-bgpmaximum load-balancing 2

7，

Huaweiip as-path-filter 1 deny ^123$

Huaweiip as-path-filter 1 permit .*

Huaweibgp 500

Huawei-bgppeer 15.1.1.1 as-path-filter 1 import

8，

Huaweiip ip-prefix cc permit 192.168.3.0 24

Huaweiroute-policy aa permit node 15

Huawei-route-policyif-match ip-prefix cc

Huawei-route-policyapply community no-export

Huaweiroute-policy bb permit node 15

Huawei-route-policyif-match ip-prefix cc

Huawei-route-policyapply community no-export