Chapter 1 What’s New for FortiOS 5.2.1 : High Availability : VRRP Support : Using a Second Destination IP (VRDST)
  
Using a Second Destination IP (VRDST)
VRRP can now be configured with second destination IP (VRDST) for monitoring. When two IPs are used, VRRP failure will only be reported if both monitored IPs are down.
A second VRDST can be configured using the CLI.
Syntax
config system interface
edit <interface>
config vrrp
edit <id>
set vrdst <ip1> <ip2>
end
end
end
end