|
我们知道ospf中有几种区域类型：stub ，totally stub ,nssa ,totally nssa. 下面分别讲一下各种区域类型对路由的改变，实验图如下:
O IA 192.168.123.0/24 [110/20] via 192.168.36.3, 00:00:04, FastEthernet0/0 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/21] via 192.168.36.3, 00:00:04, FastEthernet0/0 2.0.0.0/32 is subnetted, 1 subnets O IA 2.2.2.2 [110/21] via 192.168.36.3, 00:00:04, FastEthernet0/0 O IA 192.168.14.0/24 [110/30] via 192.168.36.3, 00:00:04, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets O 3.3.3.3 [110/11] via 192.168.36.3, 00:00:04, FastEthernet0/0 O IA 192.168.25.0/24 [110/30] via 192.168.36.3, 00:00:05, FastEthernet0/0 4.0.0.0/32 is subnetted, 1 subnets O IA 4.4.4.4 [110/31] via 192.168.36.3, 00:00:05, FastEthernet0/0 5.0.0.0/32 is subnetted, 1 subnets O IA 5.5.5.5 [110/31] via 192.168.36.3, 00:00:05, FastEthernet0/0 6.0.0.0/32 is subnetted, 1 subnets C 6.6.6.6 is directly connected, Loopback0 172.16.0.0/24 is subnetted, 4 subnets O E2 172.16.0.0 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 O E2 172.16.1.0 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 O E2 172.16.2.0 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 O E2 172.16.3.0 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 C 192.168.36.0/24 is directly connected, FastEthernet0/0 O E2 192.168.0.0/24 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 O E2 192.168.1.0/24 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 O E2 192.168.2.0/24 [110/20] via 192.168.36.3, 00:00:05, FastEthernet0/0 O E2 192.168.3.0/24 [110/20] via 192.168.36.3, 00:00:06, FastEthernet0/0 配置R3及R6 area 3 为stub区域： 配置命令为: R3(config-router)#area 3 stub R6(config-router)#area 3 stub 修改完成后，R6路由如下： O IA 192.168.123.0/24 [110/20] via 192.168.36.3, 00:00:04, FastEthernet0/0 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/21] via 192.168.36.3, 00:00:04, FastEthernet0/0 2.0.0.0/32 is subnetted, 1 subnets O IA 2.2.2.2 [110/21] via 192.168.36.3, 00:00:04, FastEthernet0/0 O IA 192.168.14.0/24 [110/30] via 192.168.36.3, 00:00:04, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets O 3.3.3.3 [110/11] via 192.168.36.3, 00:00:04, FastEthernet0/0 O IA 192.168.25.0/24 [110/30] via 192.168.36.3, 00:00:05, FastEthernet0/0 4.0.0.0/32 is subnetted, 1 subnets O IA 4.4.4.4 [110/31] via 192.168.36.3, 00:00:05, FastEthernet0/0 5.0.0.0/32 is subnetted, 1 subnets O IA 5.5.5.5 [110/31] via 192.168.36.3, 00:00:05, FastEthernet0/0 6.0.0.0/32 is subnetted, 1 subnets C 6.6.6.6 is directly connected, Loopback0 C 192.168.36.0/24 is directly connected, FastEthernet0/0 O*IA 0.0.0.0/0 [110/11] via 192.168.36.3, 00:00:07, FastEthernet0/0 由此可知stub区域不接收任何外部路由，用一条默认路由替代所有外部路由。 先在R4上查看路由表： O IA 192.168.123.0/24 [110/20] via 192.168.14.1, 00:00:51, FastEthernet0/0 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/11] via 192.168.14.1, 00:00:51, FastEthernet0/0 2.0.0.0/32 is subnetted, 1 subnets O IA 2.2.2.2 [110/21] via 192.168.14.1, 00:00:51, FastEthernet0/0 C 192.168.14.0/24 is directly connected, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets O IA 3.3.3.3 [110/21] via 192.168.14.1, 00:00:51, FastEthernet0/0 O IA 192.168.25.0/24 [110/30] via 192.168.14.1, 00:00:52, FastEthernet0/0 4.0.0.0/32 is subnetted, 1 subnets C 4.4.4.4 is directly connected, Loopback0 5.0.0.0/32 is subnetted, 1 subnets O IA 5.5.5.5 [110/31] via 192.168.14.1, 00:00:52, FastEthernet0/0 6.0.0.0/32 is subnetted, 1 subnets O IA 6.6.6.6 [110/31] via 192.168.14.1, 00:00:52, FastEthernet0/0 172.16.0.0/24 is subnetted, 4 subnets O E2 172.16.0.0 [110/20] via 192.168.14.1, 00:00:52, FastEthernet0/0 O E2 172.16.1.0 [110/20] via 192.168.14.1, 00:00:52, FastEthernet0/0 O E2 172.16.2.0 [110/20] via 192.168.14.1, 00:00:52, FastEthernet0/0 O E2 172.16.3.0 [110/20] via 192.168.14.1, 00:00:52, FastEthernet0/0 O IA 192.168.36.0/24 [110/30] via 192.168.14.1, 00:00:52, FastEthernet0/0 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 在R4和R1上运行以下命令： 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
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 2.0.0.0/32 is subnetted, 1 subnets O IA 2.2.2.2 [110/11] via 192.168.25.2, 00:35:59, FastEthernet0/0 O IA 192.168.14.0/24 [110/30] via 192.168.25.2, 00:35:59, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets O IA 3.3.3.3 [110/21] via 192.168.25.2, 00:35:59, FastEthernet0/0 C 192.168.25.0/24 is directly connected, FastEthernet0/0 4.0.0.0/32 is subnetted, 1 subnets O IA 4.4.4.4 [110/31] via 192.168.25.2, 00:02:07, FastEthernet0/0 5.0.0.0/32 is subnetted, 1 subnets C 5.5.5.5 is directly connected, Loopback0 6.0.0.0/32 is subnetted, 1 subnets O IA 6.6.6.6 [110/31] via 192.168.25.2, 00:12:47, FastEthernet0/0 172.16.0.0/24 is subnetted, 4 subnets C 172.16.0.0 is directly connected, Loopback1 C 172.16.1.0 is directly connected, Loopback1 C 172.16.2.0 is directly connected, Loopback1 C 172.16.3.0 is directly connected, Loopback1 O IA 192.168.36.0/24 [110/30] via 192.168.25.2, 00:12:47, FastEthernet0/0 O E2 192.168.0.0/24 [110/20] via 192.168.25.2, 00:02:02, FastEthernet0/0 O E2 192.168.1.0/24 [110/20] via 192.168.25.2, 00:02:02, FastEthernet0/0 O E2 192.168.2.0/24 [110/20] via 192.168.25.2, 00:02:02, FastEthernet0/0 O E2 192.168.3.0/24 [110/20] via 192.168.25.2, 00:02:02, FastEthernet0/0 在R2和R5上运行如下命令： R2(config-router)#area 1 nssa R5(config-router)#area 1 nssa O IA 192.168.123.0/24 [110/20] via 192.168.25.2, 00:00:02, FastEthernet0/0 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/21] via 192.168.25.2, 00:00:02, FastEthernet0/0 2.0.0.0/32 is subnetted, 1 subnets O IA 2.2.2.2 [110/11] via 192.168.25.2, 00:00:02, FastEthernet0/0 O IA 192.168.14.0/24 [110/30] via 192.168.25.2, 00:00:02, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets O IA 3.3.3.3 [110/21] via 192.168.25.2, 00:00:02, FastEthernet0/0 C 192.168.25.0/24 is directly connected, FastEthernet0/0 4.0.0.0/32 is subnetted, 1 subnets O IA 4.4.4.4 [110/31] via 192.168.25.2, 00:00:03, FastEthernet0/0 5.0.0.0/32 is subnetted, 1 subnets C 5.5.5.5 is directly connected, Loopback0 6.0.0.0/32 is subnetted, 1 subnets O IA 6.6.6.6 [110/31] via 192.168.25.2, 00:00:03, FastEthernet0/0 172.16.0.0/24 is subnetted, 4 subnets C 172.16.0.0 is directly connected, Loopback1 C 172.16.1.0 is directly connected, Loopback1 C 172.16.2.0 is directly connected, Loopback1 C 172.16.3.0 is directly connected, Loopback1 O IA 192.168.36.0/24 [110/30] via 192.168.25.2, 00:00:03, FastEthernet0/0 这时发现没有默认路由，需运行以下命令： R2(config-router)#area 1 nssa default-information-originate 这时R5路由如下： O IA 192.168.123.0/24 [110/20] via 192.168.25.2, 00:01:57, FastEthernet0/0 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/21] via 192.168.25.2, 00:01:57, FastEthernet0/0 2.0.0.0/32 is subnetted, 1 subnets O IA 2.2.2.2 [110/11] via 192.168.25.2, 00:01:57, FastEthernet0/0 O IA 192.168.14.0/24 [110/30] via 192.168.25.2, 00:01:57, FastEthernet0/0 3.0.0.0/32 is subnetted, 1 subnets O IA 3.3.3.3 [110/21] via 192.168.25.2, 00:01:57, FastEthernet0/0 C 192.168.25.0/24 is directly connected, FastEthernet0/0 4.0.0.0/32 is subnetted, 1 subnets O IA 4.4.4.4 [110/31] via 192.168.25.2, 00:01:59, FastEthernet0/0 5.0.0.0/32 is subnetted, 1 subnets C 5.5.5.5 is directly connected, Loopback0 6.0.0.0/32 is subnetted, 1 subnets O IA 6.6.6.6 [110/31] via 192.168.25.2, 00:01:59, FastEthernet0/0 172.16.0.0/24 is subnetted, 4 subnets C 172.16.0.0 is directly connected, Loopback1 C 172.16.1.0 is directly connected, Loopback1 C 172.16.2.0 is directly connected, Loopback1 C 172.16.3.0 is directly connected, Loopback1 O IA 192.168.36.0/24 [110/30] via 192.168.25.2, 00:01:59, FastEthernet0/0 O*N2 0.0.0.0/0 [110/1] via 192.168.25.2, 00:00:06, FastEthernet0/0 |
