实验室之OSPF篇：帧中继承载OSPF –点对点( Point-to-Point)

帧中继承载OSPF –点对点( Point-to-Point)

目标：

在R1和R2之间的帧中继网络中配置OSPF，网络类型为point-to-point，实现VLAN A和VLAN B的互通。

配置指南：

• 在R1上配置接口Ethernet0/0地址为1.0.0.1/8

• 在R2上配置接口Ethernet0/0地址为 2.0.0.2/8

• 在R1上配置接口Seria0/0地址为10.0.0.1/8

• 在R2上配置接口Seria0/0地址为10.0.0.2/8

• 使用静态三层和二层解析来配置R1和R2之间帧中继链路

• 确保链路支持广播和多播数据包传递

• 在R1和R2的Serial接口上配置OSPF网络类型为point-to-point

• 配置R1和R2中所有接口加入area 0

自我提问：

• 在多点的帧中继接口上缺省的OSPF网络类型是什么?

• point-to-point网络类型和其他网络类型有什么不同?

• hello包是单播还是组播发送?

• 支持DR/BDR 选举吗?为什么?

最终配置和验证：

R1:

interface Ethernet0/0

ip address 1.0.0.1 255.0.0.0

!

interface Serial0/0

ip address 10.0.0.1 255.0.0.0

encapsulation frame-relay

ip ospf network point-to-point

frame-relay map ip 10.0.0.2 102 broadcast

!

router ospf 1

network 0.0.0.0 255.255.255.255 area 0

 

R2:

interface Ethernet0/0

ip address 2.0.0.2 255.0.0.0

!

interface Serial0/0

ip address 10.0.0.2 255.0.0.0

encapsulation frame-relay

ip ospf network point-to-point

frame-relay map ip 10.0.0.1 201 broadcast

!

router ospf 1

network 0.0.0.0 255.255.255.255 area 0

 

R1#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

10.0.0.2 1 FULL/ - 00:00:33 10.0.0.2 Serial0/0

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

10.0.0.1 1 FULL/ - 00:00:29 10.0.0.1 Serial0/0

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, 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

O 1.0.0.0/8 [110/74] via 10.0.0.1, 00:01:08, Serial0

C 2.0.0.0/8 is directly connected, Ethernet0

C 10.0.0.0/8 is directly connected, Serial0

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, 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

C 1.0.0.0/8 is directly connected, Ethernet0

O 2.0.0.0/8 [110/74] via 10.0.0.2, 00:00:10, Serial0

C 10.0.0.0/8 is directly connected, Serial0

R1#

 

注解：

point-to-point 使用组播传送，不支持DR/BDR 选举，是点到点NBMA媒介类似ISDN和点到点子接口等的缺省网络类型。由于使用组播传递，所以在frame-relay map命令中要加上broadcast选项。