路由与交换系列之OSPF在帧中继的配置实践

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Jack20

发布于 2025-07-26 14:29:16

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【实验目的】

掌握OSPF在帧中继网络中的配置方法

理解Hub- Spoke组网架构

掌握在帧中继网络中排除OSPF故障的方法

【实验环境】

IP地址规划表

设备	接口	IP地址	子网掩码
R1	S0/0/0	10.45.123.1	255.255.255.0
R1	E0/0/0	10.45.1.1	255.255.255.0
R2	S0/0/1	10.45.123.2	255.255.255.0
R2	E0/0/0	10.45.2.1	255.255.255.0
R3	S0/0/2	10.45.123.3	255.255.255.0
R3	E0/0/0	10.45.3.1	255.255.255.0
PC1	E0/0/1	10.45.1.10	255.255.255.0
PC2	E0/0/1	10.45.2.10	255.255.255.0
PC3	E0/0/1	10.45.3.10	255.255.255.0

【实验过程】

27.1基本配置

在R1、R2、R3上配置帧帧中继接口，关闭帧中继逆向地址解析功能,其中将R1设置为DR，DR优先级为100:

AR1

<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys AR1
[AR1]link-protocol fr ietf
[AR1]int s0/0/0
[AR1-Serial0/0/0]link-protocol fr ietf
Warning: The encapsulation protocol of the link will be changed.
Continue? [Y/N]:y
[AR1-Serial0/0/0]ip add 10.45.123.1 24
[AR1-Serial0/0/0]undo fr inarp
[AR1-Serial0/0/0]fr map ip 10.45.123.2 102
[AR1-Serial0/0/0]fr map ip 10.45.123.3 103
[AR1-Serial0/0/0]ospf dr-priority 100
[AR1-Serial0/0/0]q
[AR1]int e0/0/0
[AR1-Ethernet0/0/0]ip add 10.45.1.1 24
[AR1-Ethernet0/0/0]q

AR2

<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys AR2
[AR2]int s0/0/1
[AR2-Serial0/0/1]link-protocol fr ietf
Warning: The encapsulation protocol of the link will be changed.
Continue? [Y/N]:y
[AR2-Serial0/0/1]ip add 10.45.123.2 24
[AR2-Serial0/0/1]undo fr inarp
[AR2-Serial0/0/1]fr map ip 10.45.123.1 201
[AR2-Serial0/0/1]q
[AR2]int e0/0/0
[AR2-Ethernet0/0/0]ip add 10.45.2.1 24
[AR2-Ethernet0/0/0]q

AR3

<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sys AR3
[AR3]int s0/0/2
[AR3-Serial0/0/2]link-protocol fr ietf
Warning: The encapsulation protocol of the link will be changed.
Continue? [Y/N]:y
[AR3-Serial0/0/2]ip add 10.45.123.3 24
[AR3-Serial0/0/2]undo fr inarp
[AR3-Serial0/0/2]fr map ip 10.45.123.1 301
[AR3-Serial0/0/2]q
[AR3]int e0/0/0
[AR3-Ethernet0/0/0]ip add 10.45.3.1 24
[AR3-Ethernet0/0/0]q

27.2查看帧中继的虚电路和映射表

[AR1]dis fr pvc-info
PVC statistics for interface Serial0/0/0 (DTE, physical UP)
DLCI = 102, USAGE = LOCAL (00000100), Serial0/0/0
create time = 2020/11/21 18:45:33, status = ACTIVE
InARP = Disable
in BECN = 0, in FECN = 0
in packets = 0, in bytes = 0
out packets = 1, out bytes = 30
DLCI = 103, USAGE = LOCAL (00000100), Serial0/0/0
create time = 2020/11/21 18:45:33, status = ACTIVE
InARP = Disable
in BECN = 0, in FECN = 0
in packets = 0, in bytes = 0
out packets = 1, out bytes = 30
[AR1]dis fr map-info
Map Statistics for interface Serial0/0/0 (DTE)
DLCI = 102, IP 10.45.123.2, Serial0/0/0
create time = 2020/11/21 18:45:59, status = ACTIVE
encapsulation = ietf, vlink = 3
DLCI = 103, IP 10.45.123.3, Serial0/0/0
create time = 2020/11/21 18:46:00, status = ACTIVE
encapsulation = ietf, vlink = 4

27.3测试连通性

R1和R2的连通性

R1和R2的连通性

27.4在帧中继上搭建OSPF网络

AR1

[AR1]ospf router-id 10.45.1.10
[AR1-ospf-1]area 0
[AR1-ospf-1-area-0.0.0.0]net 10.45.123.1 0.0.0.255
[AR1-ospf-1-area-0.0.0.0]net 10.45.1.10 0.0.0.255
[AR1-ospf-1-area-0.0.0.0]q
[AR1-ospf-1]q

AR2

[AR2]ospf router-id 10.45.2.10
[AR2-ospf-1]area 0
[AR2-ospf-1-area-0.0.0.0]net 10.45.123.2 0.0.0.255
[AR2-ospf-1-area-0.0.0.0]net 10.45.2.10 0.0.0.255
[AR2-ospf-1-area-0.0.0.0]q
[AR2-ospf-1]q

AR3

[AR3]ospf router-id 10.45.3.10
[AR3-ospf-1]area 0
[AR3-ospf-1-area-0.0.0.0]net 10.45.123.2 0.0.0.255
[AR3-ospf-1-area-0.0.0.0]net 10.45.3.10 0.0.0.255
[AR3-ospf-1-area-0.0.0.0]q
[AR3-ospf-1]q

27.5查看R1的邻居

[AR1]dis ospf peer
OSPF Process 1 with Router ID 10.45.1.1

发现无法正常建立邻居，这是明显的网络故障。于是我们来排查故障，排查故障时应遵循底层逐步向上层的顺序，即先检查物理层，然后二层链路层，之后高层。

物理层的检查这里省略，直接测试连通性：

[AR1]ping 10.45.123.2
PING 10.45.123.2: 56 data bytes, press CTRL_C to break
Reply from 10.45.123.2: bytes=56 Sequence=1 ttl=255 time=70 ms
Reply from 10.45.123.2: bytes=56 Sequence=2 ttl=255 time=10 ms
Reply from 10.45.123.2: bytes=56 Sequence=3 ttl=255 time=10 ms
Reply from 10.45.123.2: bytes=56 Sequence=4 ttl=255 time=110 ms
Reply from 10.45.123.2: bytes=56 Sequence=5 ttl=255 time=40 ms
--- 10.45.123.2 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 10/48/110 ms

可以观察到，直连链路没有问题，我们来检查三层路由协议，即相应接口是否被通告到OSPF进程中。

[AR1]display ospf interface
OSPF Process 1 with Router ID 10.45.1.10
Interfaces
Area: 0.0.0.0 (MPLS TE not enabled)
IP Address Type State Cost Pri DR BDR
10.45.123.1 NBMA DR 1562 100 10.45.123.1 0.0.0.0
10.45.1.1 P2P P-2-P 0 1 10.45.1.1 0.0.0.0

发现R1始终没有向外发送OSPF报文，这是因为OSPF在帧中继上默认的网络类型为NBMA，即非广播多路访问。这种类型是不支持广播和组播的，而OSPF默认时组播发送，故OSPF无法在帧中继中发送报文，无法建立邻居关系。

可以采取手工配置邻居，单播发送报文。

27.6手工配置邻居

AR1

[AR1]ospf
[AR1-ospf-1]peer 10.45.123.2
[AR1-ospf-1]peer 10.45.123.3
[AR1-ospf-1]q

AR2

[AR2]ospf
[AR2-ospf-1]peer 10.45.123.1
[AR2-ospf-1]peer 10.45.123.3
[AR2-ospf-1]q

AR3

[AR3]ospf
[AR3-ospf-1]peer 10.45.123.1
[AR3-ospf-1]peer 10.45.123.2
[AR3-ospf-1]q

查看R1的邻居关系

可以看到，邻居关系已经建立成功。

27.7配置PVC复用技术

[AR2-Serial0/0/1]fr map ip 10.45.123.3 201
[AR3-Serial0/0/2]fr map ip 10.45.123.2 301

27.8测试R2和R3的的连通性

PC>ping 10.45.123.3
Ping 10.45.123.3: 32 data bytes, Press Ctrl_C to break
From 10.45.123.3: bytes=32 seq=1 ttl=255 time=109 ms
From 10.45.123.3: bytes=32 seq=2 ttl=255 time=47 ms
From 10.45.123.3: bytes=32 seq=3 ttl=255 time=47 ms
From 10.45.123.3: bytes=32 seq=4 ttl=255 time=31 ms
From 10.45.123.3: bytes=32 seq=5 ttl=255 time=63 ms
--- 10.45.123.3 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 31/59/109 ms

知识点总结

帧中继(frame-ralay)是一种广域网技术，属于分组交换门里的一种；frame-relay是一种二层技术，与具体的物理链路无关。再说说ospf:ospf是一种动态路由协议，用以生成路由表，是众多的路由协议中较为优秀的一种，一般用再大中型企业。路由表是路由器转发数据所依赖的一张表。因此可以说没有路由协议就没有路由表，路由器就不能完成转发数据的重任。

原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。

如有侵权，请联系 cloudcommunity@tencent.com 删除。

腾讯技术创作特训营S14#红城堡

原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。

如有侵权，请联系 cloudcommunity@tencent.com 删除。

腾讯技术创作特训营S14#红城堡

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