What is the HSRP timeouts & recovery times ?

[tj6512]

How to calculate the HSRP recovery time ?

[ahojmark]

The failover time depends primarily on the 'hello' and 'holdtime' timers.

The default timers are a 3 second hello interval and a 10 second holdtime. This means, the routers will exchange hellos every 3 seconds and that a standby partner must be unreachable for 10 seconds to be declared down.

The timers are tunable with the 'standby timers' command. However, you should be careful not to tune it too agressively, as missed hellos could case both routers to go active.

[tj6512]

Thank you for your kind anwsers.

I just read from Cisco web-site that the router's interface Keepalive timer will also have a huge impact on the HSRP recovery times. So, can I deduce that the HSRP holdtime timer is essentialy same as router's interface Keepalive timer ? This is because the bottleneck for HSRP recovery time is due to how long it takes to detect (ie by deduction) that the active router interface is down.

Please help advise. Thanks !

[ahojmark]

Where did you read that?

If the secondary router doesn't hear hellos from the primary, it will go active after 'holdtime'. It doesn't really matter if the primary router's interface is up or down.

-A