一、实验拓扑：
二、网络结构：
R1 S1/2 192.168.1.1/24 lo 0 1.1.1.1/24
R2 S1/2 192.168.1.2/24 lo 0 2.2.2.2/24
R3 S1/2 192.168.1.3/24 lo 0 3.3.3.3/24
三、实验步骤
1、配置好模拟帧中继的路由器
frame-relay switching //将路由器模拟为帧中继交换机。
interface Serial1/0
no ip address
encapsulation frame-relay IETF //为接口封装帧中继。
serial restart-delay 0
clock rate 64000
no frame-relay inverse-arp
frame-relay intf-type dce//声明帧中继接口电缆类型。
frame-relay route 102 interface Serial1/1 201
frame-relay route 103 interface Serial1/2 301
//配置帧中继路由，102为进入接口的DLCI号，从S1/2的DLCI 201发出去。
!
interface Serial1/1
no ip address
encapsulation frame-relay IETF
serial restart-delay 0
clock rate 64000
no frame-relay inverse-arp
frame-relay intf-type dce
frame-relay route 201 interface Serial1/0 102
frame-relay route 203 interface Serial1/2 302
!
interface Serial1/2
no ip address
encapsulation frame-relay IETF
serial restart-delay 0
clock rate 64000
frame-relay intf-type dce
frame-relay route 301 interface Serial1/0 103
frame-relay route 302 interface Serial1/1 203
!
查看帧中继的DLCI配置路由表：
FR# sh frame-relay route
Input Intf Input Dlci Output Intf Output Dlci Status
Serial1/0 102 Serial1/1 201 active
Serial1/0 103 Serial1/2 301 active
Serial1/1 201 Serial1/0 102 active
Serial1/1 203 Serial1/2 302 active
Serial1/2 301 Serial1/0 103 active
Serial1/2 302 Serial1/1 203 active
2、对各个路由器配置对应的DLCI并连通。
R1：
interface Loopback0
ip address 1.1.1.1 255.255.255.0
ip ospf network point-to-point //将Loopback口作为网段来发布。
interface Serial1/2
ip address 192.168.1.1 255.255.255.0
encapsulation frame-relay IETF
ip ospf network broadcast //设置接口为broadcast类型，cisco专用类型。其他路由器的帧中继接口也必需设置这些命令。
serial restart-delay 0
frame-relay map ip 192.168.1.2 102 broadcast //不加broadcast，不接收广播消息，但可以发送
frame-relay map ip 192.168.1.3 103 broadcast
no frame-relay inverse-arp
R2：
interface Loopback0
ip address 2.2.2.2 255.255.255.0
ip ospf network point-to-point
interface Serial1/2
ip address 192.168.1.2 255.255.255.0
encapsulation frame-relay IETF
ip ospf network broadcast
serial restart-delay 0
frame-relay map ip 192.168.1.1 201 broadcast
frame-relay map ip 192.168.1.3 203 broadcast
no frame-relay inverse-arp
R3：
interface Loopback0
ip address 3.3.3.3 255.255.255.0
ip ospf network point-to-point
interface Serial1/2
ip address 192.168.1.3 255.255.255.0
encapsulation frame-relay IETF
ip ospf network broadcast
serial restart-delay 0
frame-relay map ip 192.168.1.1 302 broadcast
frame-relay map ip 192.168.1.2 302 broadcast
no frame-relay inverse-arp
注意与帧中继相连各个接口配置的IP地址是同一个网段的，其实相当于一个局域网内。注意R1、R2、R3与帧中继相连的接口都必须基本同样的接口类型、封装类型，不然会pinjg不通。
3、为网络配置ospf协议。
router ospf 1
network 0.0.0.0 255.255.255.255 area 0
直接将路由器的网络全部宣告入ospf网络即可。