R2(config-router)#area 2 nssa no-summary
R4(config-router)#area 2 nssa no-summary
再次查看路由表：
C 192.168.14.0/24 is directly connected, FastEthernet0/0
4.0.0.0/32 is subnetted, 1 subnets
C 4.4.4.4 is directly connected, Loopback0
C 192.168.0.0/24 is directly connected, Loopback1
C 192.168.1.0/24 is directly connected, Loopback1
C 192.168.2.0/24 is directly connected, Loopback1
C 192.168.3.0/24 is directly connected, Loopback1
O*IA 0.0.0.0/0 [110/11] via 192.168.14.1, 00:00:19, FastEthernet0/0
由此可知nssa totally 区域去掉所区域间和外部路由
先来查看一下R5路由表：
O IA 192.168.123.0/24 [110/20] via 192.168.25.2, 00:35:59, FastEthernet0/0
1.0.0.0/32 is subnetted, 1 subnets
O IA 1.1.1.1 [110/21] via 192.168.25.2, 00:35:59, FastEthernet0/0
