路由器配置成帧中继交换机

Router(config)#frame-relay switching把路由器模拟成帧中继交换机

Router(config)#inter s1/1

Router(config-if)#clock rate 128000

Router(config-if)#encapsulation frame-relay 配置接口封装帧中继

接口上启用的默认帧中继封装为Cisco封装，如果连接到非思科路由器，要使用itef参数

Router(config-if)#no shu

Router(config)#inter s1/2

Router(config-if)#clo rate 128000

Router(config-if)#encapsulation fr

Router(config-if)#no shu

changed state to upnointer s1/3

Router(config-if)#clo rate 128000

Router(config-if)#encapsulation fr

Router(config-if)#no shu

Router(config)#inter s1/1

Router(config-if)#frame-relay lmi-type cisco 配置LMI类型

Router(config-if)#frame-relay intf-type dce 配置接口为帧中继的DCE

Router(config-if)#inter s1/2

Router(config-if)#frame-relay lmi-type cisco

Router(config-if)#frame-relay intf-type dce

Router(config-if)#inter s1/3

Router(config-if)#frame-relay lmi-type cisco

Router(config-if)#frame-relay intf-type dce

配置路由器两个接口之间的pvc

Router(config)#inter s1/1

Router(config-if)#frame-relay route 103 inter s1/2 301

Router(config-if)#frame-relay route 104 inter s1/3 401

Router(config-if)#exit

Router(config)#inter s1/2

Router(config-if)#frame-relay route 301 inter s1/1 103

Router(config-if)#frame-relay route 304 inter s1/3 403

Router(config-if)#exit

Router(config)#inter s1/3

Router(config-if)#frame-relay route 401 inter s1/1 104

Router(config-if)#frame-relay route 403 inter s1/2 304

Router(config-if)#

Router#show frame-relay route

Input IntfInput DlciOutput Intf Output Dlci Status

Serial1/1 103 Serial1/2 301 active

Serial1/1 104 Serial1/3 401 active

Serial1/2 301 Serial1/1 103 active

Serial1/2 304 Serial1/3 403 active

Serial1/3 401 Serial1/1 104 active

Serial1/3 403 Serial1/2 304 active

表明路由器R2上配置3条PVC 状态都是活动的

R1的配置

Router(config)#inter s1/1

Router(config-if)#ip address 172.16.134.1 255.255.255.0

Router(config-if)#encapsulation fr 接口封装帧中继

Router(config-if)#frame-relay lmi-type cisco

Router(config)#inter fa0/0

Router(config-if)#ip add

Router(config-if)#ip address 192.168.1.1 255.255.255.0

Router(config-if)#no shu

如果采用Cisco路由器的IOS是11.2及以后的版本，路由器可以自动协商LMI是类型

所以可以不配

Router(config)#router rip

Router(config-router)#ver 2

Router(config-router)#no auto-summary

Router(config-router)#network 172.16.134.0

Router(config-router)#network 192.168.1.0

Router(config-router)#exit

R3和R4同R1

ping测试

Router#ping 172.16.134.1 source 192.168.4.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.16.134.1, timeout is 2 seconds:

Packet sent with a source address of 192.168.4.1

Success rate is 100 percent (5/5), round-trip min/avg/max = 120/155/200 ms

查看帧中继的映射

Router#show frame-relay map

Serial1/1 (up): ip 172.16.134.3 dlci 103(0x67,0x1870), dynamic,

broadcast,, status defined, active

Serial1/1 (up): ip 172.16.134.4 dlci 104(0x68,0x1880), dynamic,

broadcast,, status defined, active

以上输出显示了逆向ARP的作用结果 表明路由器R1每个封装帧中继的接口都包含2条处于活动状态的DLCI，每条都显示了远程Ip地址与本地的DLCI的映射关系

broadcast“参数允许在PVC上传输广播或组播流量 “dynamic 表明动态映射

每台路由器都不能ping通自己的串行接口的ip地址，但是可以ping通远程封装帧中继的串行接口的ip地址 是因为自己的帧中继映射表中没有自己的接口ip地址和DLCI的映射条目。 逆向ARP做动态映射解决不了该问题，只能通过静态映射解决

Router#show ip route rip

R192.168.4.0/24 [120/1] via 172.16.134.4, 00:00:07, Serial1/1

R192.168.3.0/24 [120/1] via 172.16.134.3, 00:00:27, Serial1/1

Router#show ip route rip

R192.168.4.0/24 [120/1] via 172.16.134.4, 00:00:00, Serial1/2

R192.168.1.0/24 [120/1] via 172.16.134.1, 00:00:05, Serial1/2

Router#show ip route rip

R192.168.1.0/24 [120/1] via 172.16.134.1, 00:00:18, Serial1/3

R192.168.3.0/24 [120/1] via 172.16.134.3, 00:00:27, Serial1/3

在本实验中，帧中继交换机在路由器R2上采用了PVC全互连的拓扑结构

但是在实际应用中，为了节省费用，一般采用(中心--分支)的拓扑结构

即只有分支到中心的PVC，假如R1是中心路由 R2和R3是分支路由

在R2上是配置如下

Router(config)#inter s1/2

Router(config-if)#no frame-relay route 304 interface s1/3 403

Router(config-if)#inter s1/3

Router(config-if)#no frame-relay route 403 interface s1/2 304

在R3和R4上

Router#show frame-relay map

Serial1/2 (up): ip 172.16.134.1 dlci 301(0x12D,0x48D0), dynamic,

broadcast,, status defined, active

Router#show frame-relay map

Serial1/3 (up): ip 172.16.134.1 dlci 401(0x191,0x6410), dynamic,

broadcast,, status defined, active

可以看到R3和R4上只有一条到中心站点路由器R1的映射

R4和R3的网络不可达

R1

配置帧中继的静态映射

Router(config)#inter s1/1

Router(config-if)#no frame-relay inverse-arp

关闭逆向ARP ，默认是开启的

Router(config-if)#frame-relay map ip 172.16.134.3 103 broadcast

配置帧中继静态映射

Router(config-if)#frame-relay map ip 172.16.134.4 104 broadcast

Router(config-if)#frame-relay map ip 172.16.134.1 104 broadcast

配置自己接口的ip地址的映射，目的是允许ping路由器该接口的ip地址

R3

Router(config)#inter s1/2

Router(config-if)#no frame-relay inverse-arp

Router(config-if)#frame-relay map ip 172.16.134.1 301 broadcast

Router(config-if)#frame-relay map ip 172.16.134.4 304 broadcast

Router(config-if)#frame-relay map ip 172.16.134.3 301 broadcast

R4

Router(config)#inter s1/3

Router(config-if)#no frame-relay inverse-arp

Router(config-if)#frame-relay map ip 172.16.134.1 401 broadcast

Router(config-if)#frame-relay map ip 172.16.134.3 403 broadcast

Router(config-if)#frame-relay map ip 172.16.134.4 401 broadcast

R1#show frame-relay map

Serial1/1 (up): ip 172.16.134.1 dlci 104(0x68,0x1880), static,

broadcast,

CISCO, status defined, active

Serial1/1 (up): ip 172.16.134.3 dlci 103(0x67,0x1870), static,

broadcast,

CISCO, status defined, active

Serial1/1 (up): ip 172.16.134.4 dlci 104(0x68,0x1880), static,

broadcast,

CISCO, status defined, active

R3#show frame-relay map

Serial1/2 (up): ip 172.16.134.1 dlci 301(0x12D,0x48D0), static,

broadcast,

CISCO, status defined, active

Serial1/2 (up): ip 172.16.134.3 dlci 301(0x12D,0x48D0), static,

broadcast,

CISCO, status defined, active

Serial1/2 (up): ip 172.16.134.4 dlci 301(0x12D,0x48D0), static,

broadcast,

CISCO, status defined, active

R4#show frame-relay map

Serial1/3 (up): ip 172.16.134.1 dlci 401(0x191,0x6410), static,

broadcast,

CISCO, status defined, active

Serial1/3 (up): ip 172.16.134.3 dlci 401(0x191,0x6410), static,

broadcast,

CISCO, status defined, active

Serial1/3 (up): ip 172.16.134.4 dlci 401(0x191,0x6410), static,

broadcast,

CISCO, status defined, active

封装帧中继每个接口都采用了静态映射

R1#show ip route rip

R192.168.4.0/24 [120/1] via 172.16.134.4, 00:00:26, Serial1/1

R192.168.3.0/24 [120/1] via 172.16.134.3, 00:00:07, Serial1/1

R1#show ip interface s1/1

Serial1/1 is up, line protocol is up

Internet address is 172.16.134.1/24

Broadcast address is 255.255.255.255

Split horizon is disabled接口封装帧中继后，水平分割被自动关闭

R1(R1(config)#inter s1/1

R1(config-if)#ip split-horizon 开启水平分割

R1#clear ip route * 清除路由表

R1#show ip route rip

R192.168.4.0/24 [120/1] via 172.16.134.4, 00:00:07, Serial1/1

R192.168.3.0/24 [120/1] via 172.16.134.3, 00:00:11, Serial1/1

重新获得

R3#show ip route rip

R192.168.1.0/24 [120/1] via 172.16.134.1, 00:00:15, Serial1/2

R4#show ip route rip

R192.168.1.0/24 [120/1] via 172.16.134.1, 00:00:06, Serial1/3

R3没有了R4的路由

R4没有了R3的路由