七.常见的帧中继配置（常规帧中继，背靠背帧中继，用于支撑OSPF时候的解决方案）

笔者已经在 第五篇文章中就帧中继背靠背协议的10个关键问题进行了探讨，但是，笔者感觉对于帧中继知识的归纳任稍显不足。所以特别在本文中就帧中继的各种配置需求做相关的说明。

本次的配置情况包括：（附拓扑和配置）
一.常规帧中继的配置（全互联，Hub-and-Spoken两种模式，关闭自动获取MAC功能）；
二.背靠背帧中继，以及子接口的相关帧中继配置；
三.帧中继支持OSPF环境时，ospf建邻方案（两种）
四.帧中继综合实例
一.常规帧中继的配置
1）全互联模式：R1 R2 R3 相互ping通



R1:
enable
config terminal
interface serial 0/0
no shutdown
ip address 192.168.123.1 255.255.255.0

interface serial 0/0
encapsulation frame-relay

R2:
enable
config terminal
interface serial 0/1
no shutdown
ip address 192.168.123.2 255.255.255.0

interface serial 0/1
encapsulation frame-relay

R3:
enable
config terminal
interface serial 0/2
no shutdown
ip address 192.168.123.3 255.255.255.0

interface serial 0/2
encapsulation frame-relay

FR：
enable
config terminal

frame-relay switching

interface serial 0/0
no shutdown
encapsulation frame-relay
frame-relay intf-type dce
frame-relay route 102 interface serial 0/1 201
frame-relay route 103 interface serial 0/2 301

interface serial 0/1
no shutdown
encapsulation frame-relay
frame-relay intf-type dce
frame-relay route 201 interface serial 0/0 102
frame-relay route 203 interface serial 0/2 302

interface serial 0/2
no shutdown
encapsulation frame-relay
frame-relay intf-type dce
frame-relay route 301 interface serial 0/0 103
frame-relay route 302 interface serial 0/1 203

总结：全互联中 FR 交换机（DTE）和非 FR 路由器（DCE）配置的异同：
相同点：都需要为接口封装frame-relay协议：encapsulation frame-relay
不同点：
全局上 FR要使用frame-switching开启帧中继交换功能。
接口上FR上要配置 frame-relay intf-type dce 和 frame-relay route ,无IP地址！
非FR上有IP地址，无 frame-relay intf-type dce 和 frame-relay route
2）Hub-and-Spoken：仅仅允许R1和R2,R1和R3通信

仅仅在FR做修改即可：
interface serial 0/1
no shutdown
encapsulation frame-relay
frame-relay intf-type dce
frame-relay route 201 interface serial 0/0 102

interface serial 0/2
no shutdown
encapsulation frame-relay
frame-relay intf-type dce
frame-relay route 301 interface serial 0/0 103 其他不变化及可以实现目标：

3）关闭MAC自动获取的功能：
那么需要在R1,R2,R3上做如下配置
R1:
no arp frame-relay
no frame-relay inverse-arp
frame-relay map ip 192.168.123.2 102 broadcast
frame-relay map ip 192.168.123.3 103 broadcast //此处的broadcast非常重要
R2,R3上同上。

二.背靠背帧中继（末端必须使用 不自送获取MAC地址的方式）
背靠背帧中继协议的定义：是指在帧中继交换机上的DCE端口配置IP，并且实现全网互通



如图所示：在FR上配置ip地址后，实现帧中继技术。配置如下：
R6：
interface Serial0/0
ip address 192.168.67.6 255.255.255.0
encapsulation frame-relay
frame-relay interface-dlci 200
frame-relay intf-type dce

interface Serial0/1
ip address 192.168.68.6 255.255.255.0
encapsulation frame-relay
frame-relay interface-dlci 100
frame-relay intf-type dce

R7:
interface Serial0/0
ip address 192.168.67.7 255.255.255.0
encapsulation frame-relay
no arp frame-relay
no frame-relay inverse-arp
frame-relay map ip 192.168.67.6 200 broadcast
frame-relay map ip 192.168.68.8 200 broadcast

R8:
interface Serial0/1
ip address 192.168.68.8 255.255.255.0
encapsulation frame-relay
no arp frame-relay
no frame-relay inverse-arp
frame-relay map ip 192.168.67.7 100 broadcast
frame-relay map ip 192.168.68.6 100 broadcast
这里的两条frame-relay map非常关键，分别打通了到FR和到对端的链路。

三.帧中继支持OSPF环境时，ospf建邻方案（两种）
拓扑图如下：



方法一：使用单播建立邻居关系：
R1上：（R2,R3类似）
router ospf 1
net 192.168.123.1 0.0.0.0 a 0
neighbor 192.168.123.2
neighbor 192.168.123.3
方法二：修改网络类型
R1:

interface serial 0/0
ip ospf network broadcast
R2:
interface serial 0/1
ip ospf network broadcast
R3:
interface serial 0/2
ip ospf network broadcast

四.帧中继综合实例



目标：使用两个环回口能够相互PING通
配置如下：
R3:
interface Loopback0
ip address 3.3.3.3 255.255.255.0

interface Serial0/0
ip address 192.168.35.3 255.255.255.0
encapsulation ppp
no peer neighbor-route

router eigrp 100
network 3.3.3.3 0.0.0.0
network 192.168.35.3 0.0.0.0
no auto-summary

R5:
frame-relay switching

interface Serial0/0
ip address 192.168.35.5 255.255.255.0
encapsulation ppp
no peer neighbor-route
serial restart-delay 0

interface Serial0/1
no ip address
encapsulation frame-relay
serial restart-delay 0
frame-relay intf-type dce

interface Serial0/1.99 point-to-point
ip address 192.168.51.5 255.255.255.0
frame-relay interface-dlci 99

interface Serial0/1.100 point-to-point
ip address 192.168.15.5 255.255.255.0
frame-relay interface-dlci 100

router eigrp 100
redistribute ospf 1 metric 1000 100 255 1 1500
network 192.168.15.5 0.0.0.0
network 192.168.35.5 0.0.0.0
no auto-summary

router ospf 1
network 192.168.51.5 0.0.0.0 area 0

R1:
interface Serial0/0
ip address 192.168.14.1 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
serial restart-delay 0
frame-relay map ip 192.168.24.2 300 broadcast
frame-relay map ip 192.168.14.4 300 broadcast

interface Serial0/1
no ip address
encapsulation frame-relay
serial restart-delay 0

interface Serial0/1.99 point-to-point
ip address 192.168.51.1 255.255.255.0
frame-relay interface-dlci 99

interface Serial0/1.100 point-to-point
ip address 192.168.15.1 255.255.255.0
frame-relay interface-dlci 100

router eigrp 100
network 192.168.15.1 0.0.0.0
no auto-summary

router ospf 1
log-adjacency-changes
redistribute eigrp 100 subnets
network 192.168.14.1 0.0.0.0 area 0
network 192.168.51.1 0.0.0.0 area 0

R4:
frame-relay switching

interface Serial0/0
ip address 192.168.14.4 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
serial restart-delay 0
frame-relay interface-dlci 300
frame-relay intf-type dce

interface Serial0/1
ip address 192.168.24.4 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
serial restart-delay 0
frame-relay interface-dlci 400
frame-relay intf-type dce

router ospf 1
log-adjacency-changes
network 192.168.14.4 0.0.0.0 area 0
network 192.168.24.4 0.0.0.0 area 0

R2:
interface Serial0/1
ip address 192.168.24.2 255.255.255.0
encapsulation frame-relay
ip ospf network broadcast
serial restart-delay 0
frame-relay map ip 192.168.24.4 400 broadcast
frame-relay map ip 192.168.14.1 400 broadcast

interface Serial0/2
no ip address
shutdown
serial restart-delay 0
interface Loopback0
ip address 2.2.2.2 255.255.255.0
ip ospf network point-to-point

router ospf 1
log-adjacency-changes
network 2.2.2.2 0.0.0.0 area 0
network 192.168.24.2 0.0.0.0 area 0
总结
1.在使用子接口建立PVC的时候，有几点要注意：
a.首先在在物理口上encapsulation frame-relay;frame-relay intf-type dce
b.然后 interface serial 0/0 point-to-point;frame-relay interface-dlci 100(类似于背靠背的物理接口)
或者 interface serial 0/0 multipoint;frame-relay map ip xxxxx

本文出自 “人中雨田” 博客，请务必保留此出处http://nanjingzhonglei.blog.51cto.com/5890022/1305790