Set internet failover on Fortigate 40C on firmware 5.2.3

On the Fortigate 40C, setting the dead gateway detection (aka WAN failover, aka link failover) can only be done by command line interface on firmware 5.2.3.

Why?  I have no idea.  But per support, here are the steps to create failover if WAN1 is your primary circuit:

config system link-monitor
edit 0
set srcintf "WAN1"
set server "8.8.8.8"
set protocol ping
set gateway-ip 0.0.0.0
set source-ip 0.0.0.0
set interval 5
set timeout 1
set failtime 5
set recoverytime 5
set ha-priority 1
set status enable
next
end



If you want to check status of the failover, here is the command:

diag sys link-monitor status