1、实现PC1和PC2的流量分别走R1和R2,实现负载均衡2、跟踪端口，当外部链路出现故障实现主备切换R1#conf tR1(config)#interface e0/0R1(config-if)#ip address 192.168.1.1 255.255.255.0R1(config-if)#no shutdownR1(config-if)#R1(config-if)#vrrp 10 ip 192.168.1.254 vrrp 10 号组虚拟 ip 地址R1(config-if)#vrrp 10 priority 120 设置 R1 的 vrrpIO 号组优先级为 120 (R1 成为 主路由)R1(config-if)#vrrp 10 preempt 设置抢占模式(默认开启)R1(config-if)#vrrp 20 ip 192.168.1.253 vrrp 20 号组虚拟 ip 地址R1(config-if)#vrrp 20 preempt设置抢占模式(默认开启)R1(config-if)#vrrp 20 priority 100 设置 R1 的 vrrp20 号组优先级为 100 (默认)R1#wr 保存配置R2#conf tR2(config)#interface e0/0R2(config-if)#ip add 192.168.1.2 255.255.255.0R2(config-if)#no shutdownR2(config-if)#vrrp 10 ip 192.168.1.254R2(config-if)#vrrp 10 preemptR2(config-if)#vrrp 20 ip 192.168.1.253R2(config-if)#vrrp 20 priority 120R2(config-if)#vrrp 20 preemptR2(config-if)#endR2#R2#show vrrp查看结果，R1 是 10 组的 master,R2 是 20 组的 masterEther netO/O - Group 10State is BackupVirtual IP address is 192.168.1.254Virtual MAC address is 0000.5e00.010aAdvertisement interval is 1.000 secPreemption enabledPriority is 100Master Router is 192.168.1.1, priority is 120Master Advertisement interval is 1.000 secMaster Down interval is 3.609 sec (expires in 2.813 sec)Ether netO/O - Group 20State is MasterVirtual IP address is 192.168.1.253Virtual MAC address is 0000.5e00.0114Advertisement interval is 1.000 secPreemption enabledPriority is 120Master Router is 192.168.1.2 (local), priority is 120Master Advertisement interval is 1.000 secMaster Down interval is 3.531 secR2#wr 保存配置跟踪接口，当外部网络中断，主路由切换为备份路由R1(config)#track 1 interface s1/0 line-protocol 创建跟踪对象基于链路状态 R1(config-track)#exitR1(config)#interface e0/0R1(config-if)#vrrp 10 track 1 decrement 30 跟踪对象接口，如果链路中断，优先 级降低成本30,降低后小于R2的优先级即可R1(config-if)#exitR1(config)#interface s1/0 进入外网接口，制造故障 R1(config-if)#shutdown关闭接口R1(config-if)#do show vrrp 查看 vrrp 状态 Ethernet0/0 - Group 10*State is Backup*Virtual IP address is 192.168.1.254Virtual MAC address is 0000.5e00.010aAdvertisement interval is 1.000 secPreemption enabled * Priority is 90 (cfgd 120)*Track object 1 state Down decrement 30Master Router is 192.168.1.2, priority is 100Master Advertisement interval is 1.000 secMaster Down interval is 3.531 sec (expires in 2.871 sec)如果R1由master-backup优先级由120-90 降低30.说明实验成功