把一台Cisco路由器配置为帧中继交换机
1、实验目的
通过本实验可以掌握
A.理解帧中继交换机工作原理；
B.理解PVC的概念；
C.用路由器模拟帧中继交换机的配置。
2、网络拓扑图：
3、实验步骤
本实验把路由器R2配置成帧中继交换机
(一)开启帧中继交换机功能
R2(config)#frame-relay switching
(二)配置接口封装帧中继
R2(config)#interface s0/0
R2(config-if)#clock rate 128000
R2(config-if)#encapsulation frame-relay //配置接口封装帧中继
R2(config-if)#no shutdown
【提示】
配置接口封装为帧中继，接口上启用的默认帧中继封装为Cisco封装。如果要连接到另一台Cisco路由器，则使用该选项；如果连接到非Cisco路由器，要使用ietf参数。
R2(config)#interface serial 0/1
R2(config-if)#clock rate 128000
R2(config-if)#encapsulation frame-relay
R2(config-if)#no shutdown
R2(config)#interface serial 0/2
R2(config-if)#clock rate 128000
R2(config-if)#encapsulation frame-relay
R2(config-if)#no shutdown
(三)配置帧中继LMI类型和接口类型
R2(config)#interfaces0/0
R2(config-if)#frame-relaylmi-type cisco //配置LMI类型
R2(config-if)#frame-relayintf-type dce //配置接口为帧中继的DCE
【技术要点】
A、命令“frame-relaylmi-type { cisco | ansi | q933a }”用来配置LMI的类型，默认时是Cisco类型；
B、命令“frame-relayintf-type { dce |dte }”用来配置接口是帧中继的DCE还是DTE。要注意的是：帧中继接口DCE和物理接口端是DCE还是DTE无关，也就是说即使接口是DTE端，也可以把它配置成帧中继是DCE。
R2(config)#interfaceserial 0/1
R2(config-if)#frame-relaylmi-type cisco
R2(config-if)#frame-relayintf-type dce
R2(config)#interfaceserial 0/2
R2(config-if)#frame-relaylmi-type cisco
R2(config-if)#frame-relayintf-type dce
(四)配置路由器两个接口之间的PVC
R2(config)#interfaceserial 0/0
R2(config-if)#frame-relayroute 103 interface s0/1 301
//定义接口S0/0和S0/1之间的PVC，建立帧中继交换表
R2(config-if)#frame-relayroute 104 interface s0/2 401
//定义接口S0/0和S0/2之间的PVC，建立帧中继交换表
R2(config)#interfaceserial 0/1
R2(config-if)#frame-relayroute 301 interface serial 0/0 103
R2(config-if)#frame-relayroute 304 interface serial 0/2 403
R2(config)#interfaceserial 0/2
R2(config-if)#frame-relayroute 401 interface serial 0/0 104
R2(config-if)#frame-relayroute 403 interface serial 0/1 304
4、实验调试
A、show frame-relay route
R2#shframe-relay route
InputIntf Input Dlci Output Intf Output Dlci Status
Serial0/0 103 Serial0/1 301 inactive
Serial0/0 104 Serial0/2 401 inactive
Serial0/1 301 Serial0/0 103 inactive
Serial0/1 304 Serial0/2 403 inactive
Serial0/2 401 Serial0/0 104 inactive
Serial0/2 403 Serial0/1 304 inactive
R2#
以上输出表明了路由器R2上配置了3条PVC，状态都是活动的，其中
“Serial0/0 103 Serial0/1 301 inactive”的含义是路由器如果从S0/0接口收到DLCI=103的帧，要从S0/1接口交换出去，并且DLCI被替换为301。
B、show frame-relay pvc
该命令用于显示路由器上配置的所有PVC的统计信息。
R2#shframe-relay pvc interface s0/0
PVC Statistics for interface Serial0/0 (Frame Relay DCE)
//该接口是帧中继的DCE
Active Inactive Deleted Static
Local 0 0 0 0
Switched 0 2 0 0
Unused 0 0 0 0
//输出表明该接口有2条处于活动状态的PVC
DLCI =103, DLCI USAGE = SWITCHED, PVC STATUS = INACTIVE, INTERFACE = Serial0/0
//DLCI为103的PVC处于活动状态，本地接口是S0/0，DLCI用途是完成帧中继DLCI交换
input pkts 0 output pkts 0 in bytes 0
out bytes 0 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
30 second input rate 0 bits/sec, 0packets/sec
30 second output rate 0 bits/sec, 0packets/sec
switched pkts 0
Detailed packet drop counters:
no out intf 0 out intf down 0 no out PVC 0
in PVC down 0 out PVC down 0 pkt too big 0
shaping Q full 0 pkt above DE 0 policing drop 0
pvc create time 00:28:35, last time pvcstatus changed 00:28:35
//以上输出是DLCI为103的PVC的统计信息
DLCI =104, DLCI USAGE = SWITCHED, PVC STATUS = INACTIVE, INTERFACE = Serial0/0
input pkts 0 output pkts 0 in bytes 0
out bytes 0 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
30 second input rate 0 bits/sec, 0packets/sec
30 second output rate 0 bits/sec, 0packets/sec
switched pkts 0
Detailed packet drop counters:
no out intf 0 out intf down 0 no out PVC 0
in PVC down 0 out PVC down 0 pkt too big 0
shaping Q full 0 pkt above DE 0 policing drop 0
pvc create time 00:26:45, last time pvcstatus changed 00:26:45
//以上输出是DLCI为104的PVC的统计信息
R2#
C、show frame-relay lmi
该命令用来查看LMI的统计信息。
R2#shframe-relay lmi
LMIStatistics for interface Serial0/0 (Frame Relay DCE) LMI TYPE = CISCO
//接口S0/0是帧中继的DCE,LMI类型为Cisco
Invalid Unnumbered info 0 Invalid Prot Disc 0
Invalid dummy Call Ref 0 Invalid Msg Type 0
Invalid Status Message 0 Invalid Lock Shift 0
Invalid Information ID 0 Invalid Report IE Len 0
Invalid Report Request 0 Invalid Keep IE Len 0
Num Status Enq. Rcvd 0 Num Status msgs Sent 0
//帧中继交换机收到的LMI状态查询消息的数量以及从帧中继交换机向路由器发送的LMI状态信息的数量
Num Update Status Sent 0 Num St Enq. Timeouts 232
//以上7行显示了接口S0/0的LMI的统计信息
LMIStatistics for interface Serial0/1 (Frame Relay DCE) LMI TYPE = CISCO
Invalid Unnumbered info 0 Invalid Prot Disc 0
Invalid dummy Call Ref 0 Invalid Msg Type 0
Invalid Status Message 0 Invalid Lock Shift 0
Invalid Information ID 0 Invalid Report IE Len 0
Invalid Report Request 0 Invalid Keep IE Len 0
Num Status Enq. Rcvd 0 Num Status msgs Sent 0
Num Update Status Sent 0 Num St Enq. Timeouts 185
//以上7行显示了接口S0/1的LMI的统计信息
LMIStatistics for interface Serial0/2 (Frame Relay DCE) LMI TYPE = CISCO
Invalid Unnumbered info 0 Invalid Prot Disc 0
Invalid dummy Call Ref 0 Invalid Msg Type 0
Invalid Status Message 0 Invalid Lock Shift 0
Invalid Information ID 0 Invalid Report IE Len 0
Invalid Report Request 0 Invalid Keep IE Len 0
Num Status Enq. Rcvd 0 Num Status msgs Sent 0
Num Update Status Sent 0 Num St Enq. Timeouts 181
//以上7行显示了接口S0/2的LMI的统计信息
R2#