OSPF stub
实验TOP：
实验目的：学习ospf stub的配置和作用。
一、 路由器初始配置：
1. R1上的初始配置
R1(config-line)#int s2/1
R1(config-if)#ip add 12.0.0.1 255.255.255.0
R1(config-if)#no sh
R1(config-if)#int lo 0
R1(config-if)#ip add 1.1.1.1 255.255.255.0
R1(config-if)#router os 1
R1(config-router)#router-id 1.1.1.1
R1(config-router)#net 1.1.1.1 0.0.0.0 a1
R1(config-router)#net 12.0.0.1 0.0.0.0 a 1
2. R2上的初始配置：
R2(config-line)#int s2/1
R2(config-if)#ip add 12.0.0.2 255.255.255.0
R2(config-if)#no sh
R2(config-if)#int s2/2
R2(config-if)#ip add 23.0.0.2 255.255.255.0
R2(config-if)#no sh
R2(config-if)#int lo 0
R2(config-if)#ip add 2.2.2.2 255.255.255.0
R2(config-if)#router os 1
R2(config-router)#router-id 2.2.2.2
R2(config-router)#net 2.2.2.2 0.0.0.0 a 0
R2(config-router)#net 12.0.0.2 0.0.0.0 a 1
R2(config-router)#net 23.0.0.2 0.0.0.0 a 0
3. R3上的初始配置：
R3(config-line)#int s2/1
R3(config-if)#ip add 23.0.0.3 255.255.255.0
R3(config-if)#no sh
R3(config-if)#int s2/2
R3(config-if)#ip add 34.0.0.3 255.255.255.0
R3(config-if)#no sh
R3(config-if)#int lo 0
R3(config-if)#ip add 3.3.3.3 255.255.255.0
R3(config-if)#router os 1
R3(config-router)#router-id 3.3.3.3
R3(config-router)#net 3.3.3.3 0.0.0.0 a 0
R3(config-router)#net 23.0.0.3 0.0.0.0 a 0
R3(config-router)#net 34.0.0.3 0.0.0.0 a 2
4. R4上的初始配置：
R4(config-line)#int s2/1
R4(config-if)#ip add 34.0.0.4 255.255.255.0
R4(config-if)#no sh
R4(config-if)#int lo 0
R4(config-if)#ip add 4.4.4.4 255.255.255.0
R4(config-if)#router os 1
R4(config-router)#router-id 4.4.4.4
R4(config-router)#net 4.4.4.4 0.0.0.0 a2
R4(config-router)#net 34.0.0.4 0.0.0.0 a 2
5. 查看OSPF的运行情况：
R2(config-router)#do sh ip os ne
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/ - 00:00:31 23.0.0.3 Serial2/2
1.1.1.1 0 FULL/ - 00:00:31 12.0.0.1 Serial2/1
//查看R2上路由表信息
R2(config-router)#do sh ip rout
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
34.0.0.0/24 is subnetted, 1 subnets
O IA 34.0.0.0 [110/128] via 23.0.0.3, 00:05:19, Serial2/2
1.0.0.0/32 is subnetted, 1 subnets
O 1.1.1.1 [110/65] via 12.0.0.1, 00:06:02, Serial2/1
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
3.0.0.0/32 is subnetted, 1 subnets
O 3.3.3.3 [110/65] via 23.0.0.3, 00:05:19, Serial2/2
4.0.0.0/32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/129] via 23.0.0.3, 00:04:52, Serial2/2
23.0.0.0/24 is subnetted, 1 subnets
C 23.0.0.0 is directly connected, Serial2/2
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial2/1
//查看R1上的路由表信息
R1(config-router)#do sh ip rout
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
34.0.0.0/24 is subnetted, 1 subnets
O IA 34.0.0.0 [110/192] via 12.0.0.2, 00:00:36, Serial2/1
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/65] via 12.0.0.2, 00:01:23, Serial2/1
3.0.0.0/32 is subnetted, 1 subnets
O IA 3.3.3.3 [110/129] via 12.0.0.2, 00:00:51, Serial2/1
4.0.0.0/32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/193] via 12.0.0.2, 00:00:14, Serial2/1
23.0.0.0/24 is subnetted, 1 subnets
O IA 23.0.0.0 [110/128] via 12.0.0.2, 00:01:23, Serial2/1
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial2/1
二、 实验过程：
将区域1配置为STUB区域：
R1(config-router)#area 1 stub//在R1上将区域1配置为STUB
R2(config-router)#area 1 stub//在R2上将区域1配置为STUB
三、 实验调试：
1． 重新查看R2上路由表信息
R2(config-router)#do sh ip rout
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
34.0.0.0/24 is subnetted, 1 subnets
O IA 34.0.0.0 [110/128] via 23.0.0.3, 00:02:54, Serial2/2
1.0.0.0/32 is subnetted, 1 subnets
O 1.1.1.1 [110/65] via 12.0.0.1, 00:02:54, Serial2/1
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
3.0.0.0/32 is subnetted, 1 subnets
O 3.3.3.3 [110/65] via 23.0.0.3, 00:03:09, Serial2/2
4.0.0.0/32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/129] via 23.0.0.3, 00:02:54, Serial2/2
23.0.0.0/24 is subnetted, 1 subnets
C 23.0.0.0 is directly connected, Serial2/2
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial2/1
2． 查看R1上的路由表变化：
R1(config-router)#do sh ip rou
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is 12.0.0.2 to network 0.0.0.0
34.0.0.0/24 is subnetted, 1 subnets
O IA 34.0.0.0 [110/192] via 12.0.0.2, 00:04:08, Serial2/1
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/65] via 12.0.0.2, 00:04:08, Serial2/1
3.0.0.0/32 is subnetted, 1 subnets
O IA 3.3.3.3 [110/129] via 12.0.0.2, 00:04:08, Serial2/1
4.0.0.0/32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/193] via 12.0.0.2, 00:04:08, Serial2/1
23.0.0.0/24 is subnetted, 1 subnets
O IA 23.0.0.0 [110/128] via 12.0.0.2, 00:04:08, Serial2/1
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial2/1
O*IA 0.0.0.0/0 [110/65] via 12.0.0.2, 00:04:09, Serial2/1
以上输出结果表明，R1增加了一条默认路由，指向R2的S2/1接口，如果在区域0或者1重发布其它路由信息，R1上也只会有这条默认路由。
3． 验证，在R4上重发布直连路由，在R1上查看路由表
//在R4上重建两条直连路由，并重分布到OSPF路由内
R4(config-if)#int lo 1
R4(config-if)#ip add 192.168.1.1 255.255.255.0
R4(config-if)#int lo 2
R4(config-if)#ip add 192.168.2.1 255.255.255.0
R4(config-if)#router os 1
R4(config-router)#redistribute connected subnets
//在R1上继续查看路由表
R1(config-router)#do sh ip rout
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is 12.0.0.2 to network 0.0.0.0
34.0.0.0/24 is subnetted, 1 subnets
O IA 34.0.0.0 [110/192] via 12.0.0.2, 00:11:55, Serial2/1
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/65] via 12.0.0.2, 00:11:55, Serial2/1
3.0.0.0/32 is subnetted, 1 subnets
O IA 3.3.3.3 [110/129] via 12.0.0.2, 00:11:55, Serial2/1
4.0.0.0/32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/193] via 12.0.0.2, 00:11:55, Serial2/1
23.0.0.0/24 is subnetted, 1 subnets
O IA 23.0.0.0 [110/128] via 12.0.0.2, 00:11:55, Serial2/1
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Serial2/1
O*IA 0.0.0.0/0 [110/65] via 12.0.0.2, 00:11:55, Serial2/1
以上结果表明，STUB区域过滤外部路由信息，并自动添加一条默认路由用于路由到远程网络。