被动接口与单播更新.docx

被动接口与单播更新1.实验目的通过本实验可以掌握：（1）被动接口的含义、配置和应用场合（2）单播更新的应用场合和配置2.拓扑结构实验拓扑如图 4-2 所示。由于以太口 lo1 和lo2连接主机，不需要向这些接口发送路由更新，所以可以考虑将路由器的该接口设置为被动接口。3.实验步骤（1）步骤 1：配置路由器 R1R1(config)#router ripR1(config-router)#version 1R1(config-router)#network 10.0.0.0R1(config-router)#network 172.16.0.0R1(config-router)#network 192.168.1.0R1(config-router)#passive-interface lo1R1(config-router)#passive-interface lo2（2）步骤 2：配置路由器 R2R2(config)#router ripR2(config-router)#version 1R2(config-router)#network 192.168.1.0R2(config-router)#network 2.0.0.04.实验调试R1#debug ip ripR1#clear ip route *color=#8B0000Dec 28 17:39:15.515: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.1.1)/colorDec 28 17:39:15.519: RIP: build update entriesDec 28 17:39:15.519:network 10.0.0.0 metric 1Dec 28 17:39:15.523:network 172.16.0.0 metric 1R1#Dec 28 17:39:22.095: RIP: received v1 update from 192.168.1.2 on Serial1/1Dec 28 17:39:22.095:2.0.0.0 in 1 hopsDec 28 17:39:22.979: RIP: received v1 request from 192.168.1.2 onSerial1/1Dec 28 17:39:22.983: RIP: sending v1 update to 192.168.1.2 via Serial1/1 (192.168.1.1)Dec 28 17:39:22.983: RIP: build update entriesDec 28 17:39:22.987:network 10.0.0.0 metric 1Dec 28 17:39:22.987:network 172.16.0.0 metric 1Dec 28 17:39:22.991: RIP: received v1 request from 192.168.1.2 onSerial1/1Dec 28 17:39:22.991: RIP: sending v1 update to 192.168.1.2 via Serial1/1 (192.168.1.1)Dec 28 17:39:22.999: RIP: build update entriesR1#Dec 28 17:39:23.003:network 10.0.0.0 metric 1Dec 28 17:39:23.003:network 172.16.0.0 metric 1Dec 28 17:39:23.011: RIP: received v1 request from 192.168.1.2 onSerial1/1Dec 28 17:39:23.015: RIP: sending v1 update to 192.168.1.2 via Serial1/1 (192.168.1.1)Dec 28 17:39:23.015: RIP: build update entriesDec 28 17:39:23.019:network 10.0.0.0 metric 1Dec 28 17:39:23.027:network 172.16.0.0 metric 1R1#Dec 28 17:39:25.023: RIP: received v1 update from 192.168.1.2 on Serial1/1Dec 28 17:39:25.023:2.0.0.0 in 1 hops从以上输出可以看出，路由器 R1 确实不向被动接口 lo1 和lo2 发送路由更新。 都是发向Serial1/1【技术要点】被动接口只能接收路由更新，不能以广播或组播方式发送更新，但是可以以单播的方式发送更新，配置单播更新的命令如下：R1(config-router)#neighbor A.B.C.D【实例】如图 4-3 所示，路由器 R1 只想把路由更新送到路由器 R3 上，由于 RIPv1路由协议采用广播更新， 默认情况下， 路由更新将发送给以太网上任何一个设备， 为了防止这种情况发生，把路由器 R1的 g0/0 配置成被动接口，然而路由器 R1 还想把路由更新发送给 R3，这时候必须采用单播更新，为指定的相邻路由器 R3 发送路