R1# show ip route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
B 192.168.4.0/24 [20/0] via 12.12.12.2, 00:01:04 //R7的私网路由
12.0.0.0/24 is subnetted, 1 subnets
C 12.12.12.0 is directly connected, FastEthernet0/0
C 192.168.1.0/24 is directly connected, FastEthernet0/1
47.0.0.0/24 is subnetted, 1 subnets
B 47.47.47.0 [20/0] via 12.12.12.2, 00:01:04
B 192.168.2.0/24 [20/0] via 12.12.12.2, 00:01:04 //R5的私网路由
45.0.0.0/24 is subnetted, 1 subnets
B 45.45.45.0 [20/0] via 12.12.12.2, 00:01:07