13-高级路由：OSPF DR BDR实验

Posted 2020-12-02

一、实验拓扑：

二、命令部署：
略
三、验证：
R3#show ip ospf neighbor 查看DR、BDR
R1#clear ip ospf process 清除OSPF进程

R1(config)#int f0/0
R1(config-if)#ip ospf priority 10 修改优先级

注意：增加R6，如果把200.1.1.6通告进入area 0，那么R6就是新的DR；
如果通告进area 1，那么R6是200.1.1.0的DR，R5是200.1.1.0的BDR；
这样结果，R5既是DR又是BDR，只不过在不同的网段。

1、验证：重启后/清除进程后
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 1 2WAY/DROTHER 00:00:32 100.1.1.2 FastEthernet0/0
3.3.3.3 1 2WAY/DROTHER 00:00:32 100.1.1.3 FastEthernet0/0
4.4.4.4 1 FULL/BDR 00:00:34 100.1.1.4 FastEthernet0/0
5.5.5.5 1 FULL/DR 00:00:35 100.1.1.5 FastEthernet0/0
2、验证：R1增加优先级重启后
R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 10 FULL/DR 00:00:36 100.1.1.1 FastEthernet0/0
3.3.3.3 1 2WAY/DROTHER 00:00:36 100.1.1.3 FastEthernet0/0
4.4.4.4 1 2WAY/DROTHER 00:00:36 100.1.1.4 FastEthernet0/0
5.5.5.5 1 FULL/BDR

R1(config)#int f0/0
R1(config-if)#shutdown
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 1 2WAY/DROTHER 00:00:30 100.1.1.3 FastEthernet0/0
4.4.4.4 1 FULL/BDR 00:00:34 100.1.1.4 FastEthernet0/0
5.5.5.5 1 FULL/DR 00:00:34 100.1.1.5 FastEthernet0/0
3、R3、R4把优先级改为0后
R4(config)#int f0/0
R4(config-if)#ip ospf priority 0
R3(config)#int f0/0
R3(config-if)#ip ospf priority 0

R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/DROTHER 00:00:34 100.1.1.3 FastEthernet0/0
4.4.4.4 0 FULL/DROTHER 00:00:35 100.1.1.4 FastEthernet0/0
5.5.5.5 1 FULL/DR
4、增加R6后：
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/DROTHER 00:00:38 100.1.1.3 FastEthernet0/0
4.4.4.4 0 FULL/DROTHER 00:00:38 100.1.1.4 FastEthernet0/0
5.5.5.5 1 FULL/DR 00:00:39 100.1.1.5 FastEthernet0/0

R6#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface
5.5.5.5 1 FULL/BDR 00:00:34 200.1.1.5 FastEthernet0/0