CCNA之八：背对背帧中继

 

  

环境：两台路由器，由串口相连。

要求：用两台路由器来模拟帧中继环境，fr-sw为帧中继交换机，并使用静态路由使网络联通。

 

 

步骤一：配置帧中继及联通性

 

fr-sw的配置：

fr-sw (config)#frame-relay switching       à启用帧中继交换机

fr-sw (config)#interface loopback 0

fr-sw (config-if)#ip address 1.1.1.1 255.0.0.0

fr-sw (config-if)#interface serial 0

fr-sw (config-if)#encapsulation frame-relay  à封装帧中继

fr-sw (config-if)#frame-relay intf-type dce   à时钟提供端

fr-sw (config-if)#clock rate 64000

fr-sw (config-if)#ip address 10.1.1.1 255.255.255.0

fr-sw (config-if)#frame-relay map ip 10.1.1.2 102 broadcastà启用静态映射,此DLCI号码同时也是分配给对端设备的DLCI。因此，要求两端的DLCI号码必须相同。

fr-sw (config-if)#frame-relay map ip 10.1.1.1 102 broadcastà指向自己的目的，是为了PING通本路由器的接口。

fr-sw (config-if)#no shutdown

 

r2的配置

r2(config)#interface loopback 0

r2(config-if)#ip address 2.2.2.2 255.0.0.0

r2(config-if)#interface serial0

r2(config-if)#encapsulation frame-relay

r2(config-if)#ip address 10.1.1.2 255.255.255.0

r2(config-if)#frame-relay map ip 10.1.1.1 102 broadcastà与对端相同。

r2(config-if)#frame-relay map ip 10.1.1.2 102 broadcastà与对端相同。

r2(config-if)#no shutdown

 

步骤二、配置路由

fr-sw (config)#ip route 2.2.2.0 255.255.255.0 10.1.1.2

 

r2(config)#ip route 1.1.1.0 255.255.255.0 10.1.1.1

 

步骤三、测试

fr-sw #ping ip

Target IP address: 2.2.2.2

Extended commands [n]: y

Source address or interface: 1.1.1.1

!!!!!

 

r2#ping

Protocol [ip]:

Target IP address: 1.1.1.1

Extended commands [n]: y

Source address or interface: 2.2.2.2

!!!!!

 

步骤四、查看状态

 

fr-sw的帧中继状态

fr-sw #show frame-relay pvc     à查看PVC状态

 

PVC Statistics for interface Serial0 (Frame Relay DCE)

 

              Active     Inactive      Deleted       Static

  Local          1            0            0            0

  Switched       0            0            0            0

  Unused         0            0            0            0

 

DLCI = 102, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0

 

  input pkts 69            output pkts 49           in bytes 6074

  out bytes 5052           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

  pvc create time 00:48:44, last time pvc status changed 00:47:23

 

fr-sw #show frame-relay map  à查看帧中继映射

Serial0 (up): ip 10.1.1.1 dlci 102(0x66,0x1860), static,

              broadcast,

              CISCO, status defined, active

Serial0 (up): ip 10.1.1.2 dlci 102(0x66,0x1860), static,

              broadcast,

              CISCO, status defined, active

 

r2帧中继的状态:

r2#show frame-relay pvc    à显示PVC状态

 

PVC Statistics for interface Serial0 (Frame Relay DTE)

 

              Active     Inactive      Deleted       Static

  Local          1            0            0            0

  Switched       0            0            0            0

  Unused         0            0            0            0

 

DLCI = 102, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0

 

  input pkts 26            output pkts 35           in bytes 2660

  out bytes 3137           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 9         out bcast bytes 477

  pvc create time 00:20:07, last time pvc status changed 00:20:07

 

r2#show frame-relay map    à显示帧中继映射

Serial0 (up): ip 10.1.1.1 dlci 102(0x66,0x1860), static,

              broadcast,

              CISCO, status defined, active

Serial0 (up): ip 10.1.1.2 dlci 102(0x66,0x1860), static,

              broadcast,

              CISCO, status defined, active

 

步骤五、显示当前配置

 

fr-sw的当前配置：

fr-sw #show running-config

 

hostname fr-sw

!

frame-relay switching

!

!

!

interface Loopback0

 ip address 1.1.1.1 255.255.255.0

!

interface Serial0

 ip address 10.1.1.1 255.255.255.0

 encapsulation frame-relay

 clockrate 64000

 frame-relay map ip 10.1.1.1 102 broadcast

 frame-relay map ip 10.1.1.2 102 broadcast

 frame-relay intf-type dce

!

ip route 2.2.2.0 255.255.255.0 10.1.1.2

 

!

end

 

r2的当前配置：

r2#show running-config

 

hostname r2

!

!

interface Loopback0

 ip address 2.2.2.2 255.255.255.0

!

interface Serial0

 ip address 10.1.1.2 255.255.255.0

 encapsulation frame-relay

 frame-relay map ip 10.1.1.1 102 broadcast

 frame-relay map ip 10.1.1.2 102 broadcast

!

 

ip route 1.1.1.0 255.255.255.0 10.1.1.1

 

!

end