实例如下图示：
R1: interface Loopback0 ip address 1.1.1.1 255.255.255.255 interface FastEthernet0/0 ip address 12.1.1.1 255.255.255.0 router ospf 1 router-id 1.1.1.1 area 1 nssa network 1.1.1.1 0.0.0.0 area 1 network 12.1.1.0 0.0.0.255 area 1 R2: interface Loopback0 ip address 2.2.2.2 255.255.255.255 interface FastEthernet0/0 ip address 12.1.1.2 255.255.255.0 interface FastEthernet0/1 ip address 23.1.1.2 255.255.255.0 router ospf 1 router-id 2.2.2.2 area 1 nssa default-information-originate //解决外部rip路由无法传递过来。 network 2.2.2.2 0.0.0.0 area 0 network 12.1.1.0 0.0.0.255 area 1 network 23.1.1.0 0.0.0.255 area 0 R3: interface Loopback0 ip address 3.3.3.3 255.255.255.255 interface FastEthernet0/0 ip address 34.1.1.3 255.255.255.0 interface FastEthernet0/1 ip address 23.1.1.3 255.255.255.0 router ospf 1 router-id 3.3.3.3 redistribute rip subnets network 3.3.3.3 0.0.0.0 area 0 network 23.1.1.0 0.0.0.255 area 0 router rip version 2 redistribute ospf 1 metric 2 network 34.0.0.0 no auto-summary R4: interface Loopback0 ip address 4.4.4.4 255.255.255.255 interface FastEthernet0/0 ip address 34.1.1.4 255.255.255.0 router rip
version 2 network 4.0.0.0 network 34.0.0.0 no auto-summary R4(config)#do show ip route rip 1.0.0.0/32 is subnetted, 1 subnets R 1.1.1.1 [120/2] via 34.1.1.3, 00:00:00, FastEthernet0/0 2.0.0.0/32 is subnetted, 1 subnets R 2.2.2.2 [120/2] via 34.1.1.3, 00:00:00, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets R 3.3.3.3 [120/2] via 34.1.1.3, 00:00:00, FastEthernet0/0 23.0.0.0/24 is subnetted, 1 subnets R 23.1.1.0 [120/2] via 34.1.1.3, 00:00:00, FastEthernet0/0 12.0.0.0/24 is subnetted, 1 subnets R 12.1.1.0 [120/2] via 34.1.1.3, 00:00:00, FastEthernet0/0 R4(config)#do ping 1.1.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 44/50/60 ms