目录
一、实验要求
1.使用双点双向重发布
2.所有路由器进行最佳选路
3.存在备份路径,不得出现环路和路由回馈
二、实验拓扑图
三、实验配置
1.IP地址、环回
R1:
R2: R3:
R4:
2.RIP、RIP和重发布
R1:
R2:
重发布:
R3:
R4:
重发布:
3.更改环回类型
4.书写选路策略
重发布过后会牵扯到一个选路的问题,如上图所示,去往3.3.3.0负载均衡,但是去往4.4.4.0我们要走34网段这条路,所以我们应该在R2上写路由策略,让12网段这条路增加cost值即可,因为要做备份路径
[R2]ip ip-prefix 1 permit 4.4.4.0 24
[R2]route-policy 1 permit node 10
Info: New Sequence of this List.
[R2-route-policy]if-match ip-prefix 1
[R2-route-policy]apply cost + 10
[R2-route-policy]q
[R2]route-policy 1 permit node 20
Info: New Sequence of this List.
[R2-route-policy]q
[R2-rip-1]import-route ospf 1 route-policy 1
写完回达到:
我们可以看到去往4.4.4.0网段的路只剩下一条了,而另一条路不是舍弃了而是作为备份路径使用
R1去往23网段的路同理:
[R4]ip ip-prefix 1 permit 23.1.1.0 24
[R4]route-policy 1 permit node 10
Info: New Sequence of this List.
[R4-route-policy]if-match ip-prefix 1
[R4-route-policy]apply cost
[R4-route-policy]apply cost + 10
[R4-route-policy]q
[R4]route-policy 1 permit node 20
Info: New Sequence of this List.
[R4-rip-1]import-route ospf 1 route-policy 1
效果如下:
R1去往34网段的路同理:
[R2]ip ip-prefix 2 permit 34.1.1.0 24
[R2]route-policy 1 permit node 15
Info: New Sequence of this List.
[R2-route-policy]if-match ip-prefix 2
[R2-route-policy]apply cost + 10
效果如下:
R2的选路策略:
根据type1优于type2原则,我们先将R2重发布的路由改为type1效果如下:
此时只剩一条去往14网段选路错误,所以我们还需要写一个路由策略让34网段变成type1即可
[R4]ip ip-prefix 14 permit 14.1.1.0 24
[R4]route-policy 14 permit node 10
Info: New Sequence of this List.
[R4-route-policy]if-match ip-prefix 14
[R4-route-policy]apply cost-type type-1
[R4-route-policy]apply cost - 10
[R4-route-policy]q
[R4]route-policy 14 permit node 20
Info: New Sequence of this List.
[R4-route-policy]q
[R4]ospf 1
[R4-ospf-1]import-route rip 1 route-policy 14
效果如下:
到此时选路结束,且达到最优。