Hosts are not effected by routers going down when a First Hop Redundancy Protocol like HSRP, VRRP or GLBP are used. The default gateway on the host is set to a virtual IP Address that is tied to the “active” router.
Have not received a hello message from the active router
Do not know the virtual router IP address
Neither the active nor the standby router
Receives hello message
Knows the virtual router IP address
Sends periodic hello messages
Participates in the election of the active and standby router
Knows the virtual router IP address
Candidate for active router
Sends hello message
Knows the virtual router IP address
Assumes the active forwarding of packets for the virtual router
Sends hello message
Knows the virtual router IP address
The above slide shows an example output from a show standby brief command.
The output from the slide above shows example output from a debug standby command.
Remember, the end hosts / servers point to a virtual IP Address that moves with the Active Router, hence the host is not impacted when an HSRP router fails.