Pinging the virtual IP of a backup router
When in compliance with RFC 3768 , only owner VRs reply to ping requests (ICMP echo requests) to the VIP. When the virtual IP ping option is enabled, a backup VR operating as the master can respond to ping requests made to the VIP. This makes it possible to test the availability of the default gateway with ping. A non-owner VR that is not master drops all packets to the VIP.
NOTE:
This feature is not a part of RFC 3768. Enabling this feature results in non-compliance with RFC 3768 rules.