R1
interface Ethernet0/0
ip address 192.168.1.2 255.255.255.0
half-duplex
!
interface Ethernet0/1
ip address 172.16.1.1 255.255.255.0
shutdown
half-duplex
standby 1 ip 172.16.1.100
standby 1 timers 5 15 //设置holle包超时时间，5 为五秒无hello包为超时，15为再等待15秒，15秒内无hello包则认为该端口down
standby 1 PReempt //开启抢占机制
standby 1 track Ethernet0/1 20 //跟踪E0/1接口，如果该接口down掉，则将优先级减20
R2
interface Ethernet0/0
ip address 10.0.0.2 255.255.255.0
half-duplex
!
interface Ethernet0/1
ip address 172.16.1.2 255.255.255.0
half-duplex
standby 1 ip 172.16.1.100
standby 1 timers 5 15
standby 1 priority 80
standby 1 preempt
standby 1 track Ethernet0/1 20