NBMA网络上广播模式下的OSPF部分互联
本次实验是NBMA网络上，广播模式下的OSPF，网络拓扑是部分互联的。
R1配置：
interface Loopback1
ip address 1.1.1.1 255.255.255.0
!
interface Loopback2
ip address 1.1.2.1 255.255.255.0
!
interface Serial1/0
ip address 10.0.1.1 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 1.1.1.0 0.0.0.255 area 0
network 1.1.2.0 0.0.0.255 area 0
network 10.0.1.0 0.0.0.255 area 0
!
R2配置：
interface Loopback1
ip address 2.2.1.2 255.255.255.0
!
interface Loopback2
ip address 2.2.2.2 255.255.255.0
!
interface Serial1/1
ip address 10.0.1.2 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
!
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
network 10.0.1.0 0.0.0.255 area 0
network 2.2.2.0 0.0.0.255 area 0
network 2.2.1.0 0.0.0.255 area 0
!
R3配置：
interface Loopback1
ip address 3.3.1.3 255.255.255.0
!
interface Loopback2
ip address 3.3.2.3 255.255.255.0
!
interface Serial1/2
ip address 10.0.1.3 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
!
router ospf 1
router-id 3.3.2.3
log-adjacency-changes
network 3.3.1.0 0.0.0.255 area 0
network 3.3.2.0 0.0.0.255 area 0
network 10.0.1.0 0.0.0.255 area 0
!
各个路由器的邻居关系：
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 1 FULL/DROTHER 00:00:34 10.0.1.2 Serial1/0
3.3.2.3 1 FULL/DR 00:00:39 10.0.1.3 Serial1/0
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/BDR 00:00:32 10.0.1.1 Serial1/1
R3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/BDR 00:00:35 10.0.1.1 Serial1/2
根据邻居关系可看出R3是DR，R2是DROTHER，R1是BDR
各个路由器路由表：
R1#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
1.0.0.0/24 is subnetted, 2 subnets
C 1.1.1.0 is directly connected, Loopback1
C 1.1.2.0 is directly connected, Loopback2
3.0.0.0/32 is subnetted, 2 subnets
O 3.3.1.3 [110/782] via 10.0.1.3, 00:02:32, Serial1/0
O 3.3.2.3 [110/782] via 10.0.1.3, 00:02:32, Serial1/0
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.1.0 is directly connected, Serial1/0
R2#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
2.0.0.0/24 is subnetted, 2 subnets
C 2.2.1.0 is directly connected, Loopback1
C 2.2.2.0 is directly connected, Loopback2
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.1.0 is directly connected, Serial1/1
R3#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
1.0.0.0/32 is subnetted, 2 subnets
O 1.1.1.1 [110/782] via 10.0.1.1, 00:03:17, Serial1/2
O 1.1.2.1 [110/782] via 10.0.1.1, 00:03:17, Serial1/2
3.0.0.0/24 is subnetted, 2 subnets
C 3.3.1.0 is directly connected, Loopback1
C 3.3.2.0 is directly connected, Loopback2
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.1.0 is directly connected, Serial1/2
查看路由表发现存在问题。R3不知网络中有R2，R2不知网络中有R3。R3会将路由信息发给R1，而R1不会把路由信息发给R2，R1认为R3会把路由信息发给R2，因为R3是DR。结果导致R2学不到R1和R3的路由。我们可以通过手工配置DR来让它们互相学得路由。在R2和R3的接口模式下配置ip ospf priority 0使路由器R2和R3不进行选举DR或BDR，配置如下：
R2(config)#inter s1/1
R2(config-if)#ip ospf pr
R2(config-if)#ip ospf priority 0
R3(config)#inter s1/2
R3(config-if)#ip ospf pr
R3(config-if)#ip ospf priority 0
刷新路由进程查看各个路由器路由表：
R1#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
1.0.0.0/24 is subnetted, 2 subnets
C 1.1.1.0 is directly connected, Loopback1
C 1.1.2.0 is directly connected, Loopback2
2.0.0.0/32 is subnetted, 2 subnets
O 2.2.1.2 [110/782] via 10.0.1.2, 00:08:58, Serial1/0
O 2.2.2.2 [110/782] via 10.0.1.2, 00:08:58, Serial1/0
3.0.0.0/32 is subnetted, 2 subnets
O 3.3.1.3 [110/782] via 10.0.1.3, 00:08:58, Serial1/0
O 3.3.2.3 [110/782] via 10.0.1.3, 00:08:58, Serial1/0
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.1.0 is directly connected, Serial1/0
R2#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
1.0.0.0/32 is subnetted, 2 subnets
O 1.1.1.1 [110/782] via 10.0.1.1, 00:09:43, Serial1/1
O 1.1.2.1 [110/782] via 10.0.1.1, 00:09:43, Serial1/1
2.0.0.0/24 is subnetted, 2 subnets
C 2.2.1.0 is directly connected, Loopback1
C 2.2.2.0 is directly connected, Loopback2
3.0.0.0/32 is subnetted, 2 subnets
O 3.3.1.3 [110/782] via 10.0.1.3, 00:09:33, Serial1/1
O 3.3.2.3 [110/782] via 10.0.1.3, 00:09:33, Serial1/1
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.1.0 is directly connected, Serial1/1
R3#show ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
1.0.0.0/32 is subnetted, 2 subnets
O 1.1.1.1 [110/782] via 10.0.1.1, 00:10:05, Serial1/2
O 1.1.2.1 [110/782] via 10.0.1.1, 00:10:05, Serial1/2
2.0.0.0/32 is subnetted, 2 subnets
O 2.2.1.2 [110/782] via 10.0.1.2, 00:10:05, Serial1/2
O 2.2.2.2 [110/782] via 10.0.1.2, 00:10:05, Serial1/2
3.0.0.0/24 is subnetted, 2 subnets
C 3.3.1.0 is directly connected, Loopback1
C 3.3.2.0 is directly connected, Loopback2
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.1.0 is directly connected, Serial1/2
R2有了R3的路由，R3也有了R2的路由，但它们是相互不能ping通的，因为它们找不到下一跳。
各个路由器邻居关系：
R1#show ip ospf ne
Neighbor ID Pri State Dead Time Address Interface
3.3.2.3 0 FULL/DROTHER 00:00:35 10.0.1.3 Serial1/0
2.2.2.2 0 FULL/DROTHER 00:00:32 10.0.1.2 Serial1/0
R2#show ip ospf ne
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/DR 00:00:31 10.0.1.1 Serial1/1
R3#show ip ospf ne
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/DR 00:00:35 10.0.1.1 Serial1/2