底层帧中继的搭建与配置
中间椭圆区域为帧中继云。
一、搭建帧中继云，建立R1—R4之间的帧中继连接。
1、首先将R2更改为帧中继交换机
全局下配置frame-relay switching
2、配置R2 的s0/0接口如下：
R2#sh run int s0/0
interface Serial0/0
no ip address
encapsulation frame-relay //封装帧中继
serial restart-delay 0
clock rate 64000 //配置时钟频率
frame-relay lmi-type cisco //可以不用设置，cisco路由器可以自动协商，默认为cisco
frame-relay intf-type dce //一定要更改接口类型，配置为DCE
frame-relay route 104 interface Serial0/1 401 //建立DLCI映射
end
解析frame-relay route 104 interface Serial0/1 401
104为从配置接口进的DLCI值，int s0/1为出接口，401为出接口所对应的DLCI值
R2的s0/1接口配置如s0/0，如下：
R2#sh run int s0/1
interface Serial0/1
no ip address
encapsulation frame-relay
serial restart-delay 0
clock rate 64000
frame-relay lmi-type ansi //此处更改LMI类型为ansi，DTE与DCE对应接口LMI类型必须相同
frame-relay intf-type dce
frame-relay route 401 interface Serial0/0 104
end
3、配置R1、R4
R1#sh run int s0/0
interface Serial0/0
ip address 192.168.1.1 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
frame-relay map ip 192.168.1.4 104
no frame-relay inverse-arp 手动关闭反向ARP
end
R4#sh run int s0/1
interface Serial0/1
ip address 192.168.1.4 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
frame-relay map ip 192.168.1.1 401
no frame-relay inverse-arp
end
4、查看方法
查看R2上的DLCI值映射
R2#sh frame-relay route
Input Intf Input Dlci Output Intf Output Dlci Status
Serial0/0 104 Serial0/1 401 active
Serial0/1 401 Serial0/0 104 active
可以看到接口与DLCI值的映射表
R1#ping 192.168.1.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.4, timeout is 2 seconds:
!!!!!
二、配置R1—R5的帧中继云
由于帧中继帧中继云中，R2和R3是由交换机相连，且帧中继的接口不支持在以太口上配置
R2(config-if)#frame-relay route 105 interface ?
MFR Multilink Frame Relay bundle interface
Serial Serial
Tunnel Tunnel interface
所以在此处我们新建一个tunnel，将R2到R3之间的数据用隧道进行封装
1、 首先为R2的f1/0配置IP地址
interface FastEthernet1/0
ip address 192.168.23.2 255.255.255.0
2、 创建interface tunnel 10
R2#sh run int tunnel 10
interface Tunnel10
no ip address
tunnel source FastEthernet1/0 //隧道的源点
tunnel destination 192.168.23.3 //隧道的出口
end
3、 在R2的s0/0接口上配置R1—R5的映射
R2#sh run int s0/0
interface Serial0/0
no ip address
encapsulation frame-relay
serial restart-delay 0
clock rate 64000
frame-relay lmi-type cisco
frame-relay intf-type dce
frame-relay route 104 interface Serial0/1 401
frame-relay route 105 interface Tunnel10 100
end
解析：frame-relay route 105 interface Tunnel10 100
此处的100 同样也是出接口的DLCI值，是R2和R3之间的DLCI值，其中间转换作用
R3上同样配置如下：
R3# sh run int s0/0
Building configuration...
interface Serial0/0
no ip address
encapsulation frame-relay
serial restart-delay 0
clock rate 64000
frame-relay lmi-type ansi
frame-relay intf-type dce
frame-relay route 501 interface Tunnel10 100
end
4、 查看R3上的映射
R3#sh frame-relay route
Input Intf Input Dlci Output Intf Output Dlci Status
Serial0/0 501 Tunnel10 100 active
Tunnel10 100 Serial0/0 501 active
5、 验证R1到R5的路径
R1#trace 192.168.1.5
Type escape sequence to abort.
Tracing the route to 192.168.1.5
1 192.168.1.5 460 msec * 188 msec