配置好基本信息，测通继续。

在R3(ASBR：自治系统边界路由器)上的配置：

R3(config)#router ospf 1
R3(config-router)#network 192.168.1.4 0.0.0.3 a 0
R3(config-router)#exit
R3(config)#router rip 
R3(config-router)#network 172.16.0.0
R3(config-router)#exit

各设备路由表：

R1#show ip route
Gateway of last resort is not set

     10.0.0.0/24 is subnetted, 2 subnets
C       10.1.2.0 is directly connected, Loopback1
C       10.1.1.0 is directly connected, Loopback0
     192.168.1.0/30 is subnetted, 2 subnets
C       192.168.1.0 is directly connected, Serial0/0
O IA    192.168.1.4 [110/128] via 192.168.1.2, 00:06:34, Serial0/0

R2#show ip route
Gateway of last resort is not set

     10.0.0.0/32 is subnetted, 2 subnets
O       10.1.2.1 [110/65] via 192.168.1.1, 00:06:40, Serial0/0
O       10.1.1.1 [110/65] via 192.168.1.1, 00:06:40, Serial0/0
     192.168.1.0/30 is subnetted, 2 subnets
C       192.168.1.0 is directly connected, Serial0/0
C       192.168.1.4 is directly connected, Serial0/1

R3#show ip route
Gateway of last resort is not set

     172.16.0.0/24 is subnetted, 3 subnets
C       172.16.1.0 is directly connected, Serial0/1
R       172.16.2.0 [120/1] via 172.16.1.2, 00:00:22, Serial0/1
R       172.16.3.0 [120/1] via 172.16.1.2, 00:00:22, Serial0/1
     10.0.0.0/32 is subnetted, 2 subnets
O IA    10.1.2.1 [110/129] via 192.168.1.5, 00:03:33, Serial0/0
O IA    10.1.1.1 [110/129] via 192.168.1.5, 00:03:33, Serial0/0
     192.168.1.0/30 is subnetted, 2 subnets
O IA    192.168.1.0 [110/128] via 192.168.1.5, 00:03:33, Serial0/0
C       192.168.1.4 is directly connected, Serial0/0

R4#show ip route
Gateway of last resort is not set

     172.16.0.0/24 is subnetted, 3 subnets
C       172.16.1.0 is directly connected, Serial0/0
C       172.16.2.0 is directly connected, Loopback0
C       172.16.3.0 is directly connected, Loopback1

R4只有直连路由，R1和R2没有RIP区域的路由，所以它们不能测通RIP区的地址：

R1#ping 192.168.1.6

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.6, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/40/60 ms
R1#ping 172.16.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

在R3 上配置重分发：

R3(config)#router ospf 1 
R3(config-router)#redistribute rip metric 200 subnets
R3(config-router)#exit
R3(config)#router rip
R3(config-router)#redistribute ospf 1 metric 10
R3(config-router)#exit

查看R1 / R4路由器路由表并使用ping 命令确认路由：

R1#show ip route
Gateway of last resort is not set

     172.16.0.0/24 is subnetted, 3 subnets
O E2    172.16.1.0 [110/200] via 192.168.1.2, 00:01:46, Serial0/0
O E2    172.16.2.0 [110/200] via 192.168.1.2, 00:01:46, Serial0/0
O E2    172.16.3.0 [110/200] via 192.168.1.2, 00:01:46, Serial0/0
     10.0.0.0/24 is subnetted, 2 subnets
C       10.1.2.0 is directly connected, Loopback1
C       10.1.1.0 is directly connected, Loopback0
     192.168.1.0/30 is subnetted, 2 subnets
C       192.168.1.0 is directly connected, Serial0/0
O IA    192.168.1.4 [110/128] via 192.168.1.2, 01:39:03, Serial0/0

R1#ping 172.16.2.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/63/96 ms

R4#show ip route 
Gateway of last resort is not set

     172.16.0.0/24 is subnetted, 3 subnets
C       172.16.1.0 is directly connected, Serial0/0
C       172.16.2.0 is directly connected, Loopback0
C       172.16.3.0 is directly connected, Loopback1
R    10.0.0.0/8 [120/10] via 172.16.1.1, 00:00:06, Serial0/0
R    192.168.1.0/24 [120/10] via 172.16.1.1, 00:00:06, Serial0/0

现在学习到的外网路由已经是E2的类型。此时显示的cost 值为200（配置的时候手动指定200），其中没有包含了到达R3 的cost。
如果学到的外网路由是E1类型，则会加上到达R3的cost：200+128=328

查看R1 路由器的链路状态数据库：

在R1中显示外网路由为3条，为了减少路由条目，可在R3上汇总外部路由：

R3(config)#router ospf 1
R3(config-router)#summary-address 172.16.0.0 255.255.0.0
R3(config-router)#exit

再查看R1的路由表：

R1# show ip route
Gateway of last resort is not set

O E2 172.16.0.0/16 [110/200] via 192.168.1.2, 00:00:21, Serial0/0
     10.0.0.0/24 is subnetted, 2 subnets
C       10.1.2.0 is directly connected, Loopback1
C       10.1.1.0 is directly connected, Loopback0
     192.168.1.0/30 is subnetted, 2 subnets
C       192.168.1.0 is directly connected, Serial0/0
O IA    192.168.1.4 [110/128] via 192.168.1.2, 01:53:10, Serial0/0

确认汇总成功。