试验拓扑：
试验要求：
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
spoke
路由器，
R1
采用点对多点子接口，
R2
用物理接口，
R3
用点对点子接口，全部起
OSPF
。
试验目的：一是掌握
NBMA
部分网格环境下，采用点对点子接口时，
OSPF
的配置方法，二是掌握不同接口类型是否可以成功建立邻居关系。
实验配置：
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 multipoint
R1(config-subif)#ip add 199.99.1.1 255.255.255.0
R1(config-subif)#frame-relay map ip 199.99.1.2 301 broadcast
R1(config-subif)#frame-relay map ip 199.99.1.3 302 broadcast
R2
：
R2(config)#int s1/0
R2(config-if)#enca frame-relay
R2(config-if)#ip add 199.99.1.2 255.255.255.0
R2(config-if)#no frame-relay inverse-arp
R2(config-if)#frame-relay map ip 199.99.1.1 103 broadcast
R2(config-if)#frame-relay map ip 199.99.1.2 103 broadcast
R2(config-if)#frame-relay map ip 199.99.1.3 103 broadcast
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 199.99.1.3 255.255.255.0
R3(config-subif)#frame-relay interface-dlci 203
基本的链路层配置完成，先验证连通性：
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 = 144/204/356 ms
R1#ping 199.99.1.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 199.99.1.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 144/191/216 ms
好了，连路都是通的，下面开始
OSPF
的配置：
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 0.0.0.0 255.255.255.255 area 0
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 0.0.0.0 255.255.255.255 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 0.0.0.0 255.255.255.255 area 0
配置完成后，用
show ip ospf interface
查看接口
OSPF
配置：
R1#show ip ospf interface
Loopback0 is up, line protocol is up
Internet Address 100.100.100.100/24, Area 0
Process ID 100, Router ID 100.100.100.100, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
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 NON_BROADCAST, Cost: 64
Transmit Delay is 1 sec, State WAITING, Priority 1
No designated router on this network
No backup designated router on this network
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:02
Wait time before Designated router selection 00:01:02
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
R2#show ip ospf interface
Loopback0 is up, line protocol is up
Internet Address 2.2.2.2/24, Area 0
Process ID 100, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
Serial1/0 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 NON_BROADCAST, Cost: 64
Transmit Delay is 1 sec, State WAITING, Priority 1
No designated router on this network
No backup designated router on this network
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:11
Wait time before Designated router selection 00:01:11
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
R3#show ip ospf interface
Loopback0 is up, line protocol is up
Internet Address 3.3.3.3/24, Area 0
Process ID 100, Router ID 3.3.3.3, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
Serial1/0.1 is up, line protocol is up
Internet Address 199.99.1.3/24, 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 00:00:02
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
注意用红色标记的部分：
R1
接口的网络类型为
NON_BROADCAST
，
R2
为
NON_BROADCAST
，
R3
为
POINT_TO_POINT
。然后查看邻居表会发现无法建立邻居关系。
Debug
信息会显示接口类型不匹配，所以无法建立邻居关系，下面手动修改接口网络类型为
POINT_TO_MULTIPOINT
：
R1(config)#int s1/0.1 multipoint
R1(config-subif)#ip ospf network point-to-multipoint
R2(config)#int s1/0
R2(config-if)#ip ospf network point-to-multipoint
R3(config)#int s1/0.1 point-to-point
R3(config-subif)#ip ospf network point-to-multipoint
这样修改完成后，再用
show ip ospf interface
命令查看接口网络类型：
R1#show ip ospf interface
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_MULTIPOINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT,
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:10
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 2, Adjacent neighbor count is 1
Adjacent with neighbor 3.3.3.3
Suppress hello for 0 neighbor(s)
Loopback0 is up, line protocol is up
Internet Address 100.100.100.100/24, Area 0
Process ID 100, Router ID 100.100.100.100, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
R2#show ip ospf interface
Serial1/0 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_MULTIPOINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT,
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:12
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)
Loopback0 is up, line protocol is up
Internet Address 2.2.2.2/24, Area 0
Process ID 100, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
R3#show ip ospf interface
Serial1/0.1 is up, line protocol is up
Internet Address 199.99.1.3/24, Area 0
Process ID 100, Router ID 3.3.3.3, Network Type POINT_TO_MULTIPOINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_MULTIPOINT,
Timer intervals configured, Hello 30, Dead 120, Wait 120, Retransmit 5
oob-resync timeout 120
Hello due in 00:00:15
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 4 msec, maximum is 4 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 100.100.100.100
Suppress hello for 0 neighbor(s)
Loopback0 is up, line protocol is up
Internet Address 3.3.3.3/24, Area 0
Process ID 100, Router ID 3.3.3.3, Network Type POINT_TO_POINT, Cost: 1
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Supports Link-local Signaling (LLS)
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 0, maximum is 0
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 0, Adjacent neighbor count is 0
Suppress hello for 0 neighbor(s)
上面用红颜色标记的部分不仅显示了接口的网络类型为
POINT_TO_MULTIPOINT
，还显示了
默认的
HELLO
时间间隔为
30
秒，等待时间和死亡时间为
HELLO
时间间隔的
4
倍
120
秒
，然后在用
show ip ospf neighbor
查看邻居关系：
R1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3
.3 0 FULL/ - 00:01:59 199.99.1.3 Serial1/0.1
2.2.2
.2 0 FULL/ - 00:01:57 199.99.1.2 Serial1/0.1
R2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
100.100.100.100 0 FULL/ - 00:01:58 199.99.1.1 Serial1/0
R3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
100.100.100.100 0 FULL/ - 00:01:50 199.99.1.1 Serial1/0.1
邻居关系自动建立，并且不需要选举
DR/BDR
，
sopke
路由器只和
hub
路由器建立邻居关系，
最后查看一下每台路由器的路由表：
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
3.0.0.0/24 is subnetted, 1 subnets
O 3.3.3.0 [110/65] via 199.99.1.3, 00:00:10, Serial1/0.1
199.99.1.0/24 is variably subnetted, 2 subnets, 2 masks
C 199.99.1.0/24 is directly connected, Serial1/0.1
O 199.99.1.3/32 [110/64] via 199.99.1.3, 00:00:10, 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
100.0.0.0/24 is subnetted, 1 subnets
O 100.100.100.0 [110/65] via 199.99.1.1, 00:00:05, Serial1/0
3.0.0.0/24 is subnetted, 1 subnets
O 3.3.3.0 [110/129] via 199.99.1.1, 00:00:05, Serial1/0
199.99.1.0/24 is variably subnetted, 3 subnets, 2 masks
O 199.99.1.1/32 [110/64] via 199.99.1.1, 00:00:05, Serial1/0
C 199.99.1.0/24 is directly connected, Serial1/0
O 199.99.1.3/32 [110/128] via 199.99.1.1, 00:00:05, Serial1/0
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
2.0.0.0/24 is subnetted, 1 subnets
O 2.2.2.0 [110/129] via 199.99.1.1, 00:00:10, Serial1/0.1
100.0.0.0/24 is subnetted, 1 subnets
O 100.100.100.0 [110/65] via 199.99.1.1, 00:00:10, Serial1/0.1
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
199.99.1.0/24 is variably subnetted, 3 subnets, 2 masks
O 199.99.1.1/32 [110/64] via 199.99.1.1, 00:00:11, Serial1/0.1
C 199.99.1.0/24 is directly connected, Serial1/0.1
O 199.99.1.2/32 [110/128] via 199.99.1.1, 00:00:11, Serial1/0.1
实验总结：
掌握在
NBMA
模式下，采用点对多点子接口的时候
OSPF
路由协议的配置，并且邻居关系是自动建立，无需手动指定邻居，无
DR/BDR
选举，默认的
HELLO
时间间隔为
30
秒，等待时间和死亡时间为
HELLO
时间间隔的
4
倍，
120
秒。还有就是接口地址是以
32
位主机路由的方式泛洪出去的。
本文转自loveme2351CTO博客，原文链接：
http://blog.51cto.com/loveme23/46307
，如需转载请自行联系原作者
