CCNP-8 OSPF试验4
试验拓扑：
实验要求：R1 R2 R3通过FR相连，形成hub and spoke网络拓扑，R1为hub路由器，R2 R3为sopke路由器，要求R1 R2 R3全部采用点对点子接口，全部起OSPF。
试验目的：掌握OSPF在NBMA环境下采用点对点子接口的配置。
试验配置：
R1：
R1(config)#int s1/0
R1(config-if)#enca frame-relay
R1(config-if)#no shu
R1(config-if)#exit
R1(config)#int s1/0.1 point-to-point
R1(config-subif)#ip add 199.99.1.1 255.255.255.0
R1(config-subif)#frame-relay interface-dlci 301
R1(config-fr-dlci)#exit
R1(config-subif)#no shu
R1(config-subif)#exit
R1(config)#int s1/0.2 point-to-point
R1(config-subif)#ip add 199.99.2.1 255.255.255.0
R1(config-subif)#frame-relay interface-dlci 302
R1(config-fr-dlci)#exit
R1(config-subif)#no shu
R1(config-subif)#exit
R2：
R2(config)#int s1/0
R2(config-if)#enca frame-relay
R2(config-if)#no shu
R2(config-if)#exit
R2(config)#int s1/0.1 point-to-point
R2(config-subif)#ip add 199.99.1.2 255.255.255.0
R2(config-subif)#frame-relay interface-dlci 103
R2(config-fr-dlci)#exit
R2(config-subif)#no shu
R2(config-subif)#exit
R3：
R3(config)#int s1/0
R3(config-if)#enca frame-relay
R3(config-if)#no shu
R3(config-if)#exit
R3(config)#int s1/0.1 point-to-point
R3(config-subif)#ip add 199.99.2.2 255.255.255.0
R3(config-subif)#frame-relay interface-dlci 203
R3(config-fr-dlci)#exit
R3(config-subif)#no shu
R3(config-subif)#exit
基本的链路层配置完成，先测试一下连通性：
R1#ping 199.99.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 199.99.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 144/204/240 ms
R1#ping 199.99.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 199.99.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 240/253/264 ms
OK，都通了，下面开始配置OSPF：
R1(config)#int loop0
R1(config-if)#ip add 100.100.100.100 255.255.255.0
R1(config-if)#ip ospf network point-to-point
R1(config-if)#exit
R1(config)#router ospf 100
R1(config-router)#router-id 100.100.100.100
R1(config-router)#network 199.99.1.0 0.0.0.255 area 0
R1(config-router)#network 199.99.2.0 0.0.0.255 area 0
R1(config-router)#exit
R2(config)#int loop0
R2(config-if)#ip add 2.2.2.2 255.255.255.0
R2(config-if)#ip ospf network point-to-point
R2(config-if)#exit
R2(config)#router ospf 100
R2(config-router)#router-id 2.2.2.2
R2(config-router)#network 199.99.1.0 0.0.0.255 area 0
R3(config)#int loop0
R3(config-if)#ip add 3.3.3.3 255.255.255.0
R3(config-if)#ip ospf network point-to-point
R3(config-if)#exit
R3(config)#router ospf 100
R3(config-router)#router-id 3.3.3.3
R3(config-router)#network 199.99.2.0 0.0.0.255 area 0
R3(config-router)#exit
好了，我们先等一会，看看在点对点环境下邻居关系是否会自动建立，不用说当让会自动建立邻居关系了，下面查看一下各自的路由表：
R1#show ip route
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
100.0.0.0/24 is subnetted, 1 subnets
C 100.100.100.0 is directly connected, Loopback0
C 199.99.2.0/24 is directly connected, Serial1/0.2
C 199.99.1.0/24 is directly connected, Serial1/0.1
R2#show ip route
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
2.0.0.0/24 is subnetted, 1 subnets
C 2.2.2.0 is directly connected, Loopback0
O 199.99.2.0/24 [110/128] via 199.99.1.1, 00:00:05, Serial1/0.1
C 199.99.1.0/24 is directly connected, Serial1/0.1
R3#show ip route
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
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
C 199.99.2.0/24 is directly connected, Serial1/0.1
O 199.99.1.0/24 [110/128] via 199.99.2.1, 00:00:00, Serial1/0.1
在两台spoke路由器上都看到了”O”路由，证明OSPF路由协议运行正常，下面show ip ospf interface查看一下接口的OSPF运行情况：
R1#show ip ospf interface
Serial1/0.2 is up, line protocol is up
Internet Address 199.99.2.1/24, Area 0
Process ID 100, Router ID 100.100.100.100, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:03
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 3.3.3.3
Suppress hello for 0 neighbor(s)
Serial1/0.1 is up, line protocol is up
Internet Address 199.99.1.1/24, Area 0
Process ID 100, Router ID 100.100.100.100, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:03
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 4 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 2.2.2.2
Suppress hello for 0 neighbor(s)
R2#show ip ospf interface
Serial1/0.1 is up, line protocol is up
Internet Address 199.99.1.2/24, Area 0
Process ID 100, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:08
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 100.100.100.100
Suppress hello for 0 neighbor(s)
R3#show ip ospf interface
Serial1/0.1 is up, line protocol is up
Internet Address 199.99.2.2/24, Area 0
Process ID 100, Router ID 3.3.3.3, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:07
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 100.100.100.100
Suppress hello for 0 neighbor(s)
上面的输出包含了很多重要的信息：点对电子接口的网络类型为POINT_TO_POINT，默认的HELLO时间间隔为10秒，等待时间和死亡时间为HELLO时间间隔的4倍40秒，各自邻居的router-id等等，要看懂上面的每一条信息，下面查看邻居表：
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/ - 00:00:30 199.99.2.2 Serial1/0.2
2.2.2.2 0 FULL/ - 00:00:39 199.99.1.2 Serial1/0.1
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
100.100.100.100 0 FULL/ - 00:00:30 199.99.1.1 Serial1/0.1
R3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
100.100.100.100 0 FULL/ - 00:00:38 199.99.2.1 Serial1/0.1
通过邻居表和我们之前的配置可以知道在NBMA点对点子接口的环境下，邻居关系是自动建立的，无需手动添加，并且是没有DR/BDR选举存在。
实验总结：掌握在NBMA点对点子接口环境下配置OSPF的方法，并且知道在NBMA点对点环境下邻居关系是自动建立的，并且没有DR/BDR选举，默认得HELLO时间间隔为10秒，等待时间和死亡时间为HELLO时间间隔的4倍40秒
本文转自loveme2351CTO博客，原文链接：http://blog.51cto.com/loveme23/46190 ，如需转载请自行联系原作者
