一、实验拓扑：
二、实验要求：
1、R1、R2、R3运行EIGRP 90；
2、R1、R2在接口f1/0下部署Standby 1，并设置192.168.10.254的主备网关；
3、实验目的：验证standby状态、邻居状态机
三、命令部署：
四、验证：
1、R2的优先级为200，R3的优先级为100
R2#show standby bri
P indicates configured to preempt.
|
Interface Grp Prio P State Active Standby Virtual IP
Fa1/0 1 200 Active local 192.168.10.252 192.168.10.254
R3#show standby brief
P indicates configured to preempt.
|
Interface Grp Prio P State Active Standby Virtual IP
Fa1/0 1 100 P Standby 192.168.10.253 local 192.168.10.254
结论：R2处于Active状态，R3处于Standby状态
2、R2接口down掉的时候：
R2(config)#int f1/0
R2(config-if)#shutdown
R2(config-if)#
*Mar 1 00:22:48.463: %HSRP-6-STATECHANGE: FastEthernet1/0 Grp 1 state Active -> Init
PC-1>ping 1.1.1.1 -c 20000
84 bytes from 1.1.1.1 icmp_seq=297 ttl=254 time=28.924 ms
1.1.1.1 icmp_seq=298 timeout
1.1.1.1 icmp_seq=299 timeout
1.1.1.1 icmp_seq=300 timeout
1.1.1.1 icmp_seq=301 timeout
1.1.1.1 icmp_seq=302 timeout
1.1.1.1 icmp_seq=303 timeout
84 bytes from 1.1.1.1 icmp_seq=304 ttl=254 time=27.893 ms
结论：R2会从Active变为Init状态，同时R3会有Coup政变和Resign辞职包，这里都是2个AD包
3、当R3优先级变为255时候：
R2#
*Mar 1 00:06:12.259: %HSRP-6-STATECHANGE: FastEthernet1/0 Grp 1 state Active -> Speak
R2#
*Mar 1 00:06:22.259: %HSRP-6-STATECHANGE: FastEthernet1/0 Grp 1 state Speak -> Standby
R2#show standby bri
P indicates configured to preempt.
|
Interface Grp Prio P State Active Standby Virtual IP
Fa1/0 1 200 Standby 192.168.10.252 local 192.168.10.254
R3(config-if)#
*Mar 1 00:06:02.251: %HSRP-6-STATECHANGE: FastEthernet1/0 Grp 1 state Standby -> Active
R3#show standby bri
P indicates configured to preempt.
|
Interface Grp Prio P State Active Standby Virtual IP
Fa1/0 1 255 P Active local 192.168.10.253 192.168.10.254
结论：R2从Active侦听到有更高的优先级，所以变为Speak，然后变为Standby
R3因为优先级最高，并且开启了抢占，从Standby变为Active
