双点双向重发布：
做配置：观察四个路由器上的路由发现
R1
路由：
1.0.0 .0/24 is subnetted, 1 subnets
C 1.1.1 .0 is directly connected, Loopback0
35.0.0.0/24 is subnetted, 1 subnets
D EX 35.1.1.0 [170/2588160] via 192.168.1.3, 00:02:22, FastEthernet0/0
[170/2588160] via 192.168.1.2, 00:02:22, FastEthernet0/0
5.0.0 .0/24 is subnetted, 1 subnets
D EX 5.5.5 .0 [170/2588160] via 192.168.1.3, 00:02:22, FastEthernet0/0
[170/2588160] via 192.168.1.2, 00:02:22, FastEthernet0/0
25.0.0.0/24 is subnetted, 1 subnets
D EX 25.1.1.0 [170/2588160] via 192.168.1.2, 00:02:41, FastEthernet0/0
[170/2588160] via 192.168.1.3, 00:02:41, FastEthernet0/0
C 192.168.1.0/24 is directly connected, FastEthernet0/0
R2
路由：
1.0.0 .0/24 is subnetted, 1 subnets
D EX 1.1.1 .0 [170/156160] via 192.168.1.1, 00:03:45, FastEthernet0/0
35.0.0.0/24 is subnetted, 1 subnets
O 35.1.1.0 [110/128] via 25.1.1.2, 00:03:27, Serial1/2
5.0.0 .0/24 is subnetted, 1 subnets
O E2 5.5.5 .0 [110/20] via 25.1.1.2, 00:03:27, Serial1/2
25.0.0.0/24 is subnetted, 1 subnets
C 25.1.1.0 is directly connected, Serial1/2
C 192.168.1.0/24 is directly connected, FastEthernet0/0
R3
路由：
1.0.0 .0/24 is subnetted, 1 subnets
O E2 1.1.1 .0 [110/20] via 35.1.1.2, 00:04:02, Serial1/2
35.0.0.0/24 is subnetted, 1 subnets
C 35.1.1.0 is directly connected, Serial1/2
5.0.0 .0/24 is subnetted, 1 subnets
O E2 5.5.5 .0 [110/20].1.2, 00:04:02, Serial1/2
25.0.0.0/24 is subnetted, 1 subn via 35.1ets
O 25.1.1.0 [110/128] via 35.1.1.2, 00:04:02, Serial1/2
C 192.168.1.0/24 is directly connected, FastEthernet0/0
R4
路由：
1.0.0 .0/24 is subnetted, 1 subnets
O E2 1.1.1 .0 [110/20] via 25.1.1.1, 00:04:17, Serial1/1
35.0.0.0/24 is subnetted, 1 subnets
C 35.1.1.0 is directly connected, Serial1/2
5.0.0 .0/24 is subnetted, 1 subnets
C 5.5.5 .0 is directly connected, Loopback0
25.0.0.0/24 is subnetted, 1 subnets
C 25.1.1.0 is directly connected, Serial1/1
O E2 192.168.1.0/24 [110/20] via 25.1.1.1, 00:21:48, Serial1/1
[110/20] via 35.1.1.1, 00:21:48, Serial1/2
观察红色的部分 发现 1.1.1 .0网段没有负载均衡 但是5.5.5.0网段负载均衡了，因为在我们做R2上的路由重发布的时候 ospf的管理距离为110 但是R2也会通过R1学到路由 但是这个时候R3上也有
1.1.1
.0
网段的路由这个是EX的路由管理距离为170 大于ospf的距离所以路由器选择管理距离小的 才出现在R2 R3上的橙色部分的路由显示 所以不可能负载均衡