Re: how can find failover at version 5.4
I, personally, would do this.
create a zone titled OUTSIDE
place primary internet provider and secondary internet provider in there.
Create two default routes, one to the primary and one to the secondary. Make the secondary have a slightly higher "priority" which in FortiOS just means cost.
Configure link health monitoring through CLI for each connection. If primary WAN fails the configured number of times then it will yank the route and use the backup line.
below is how to configure the link monitor
config system link-monitor
set srcintf "wan1"
set server "126.96.36.199"
set interval 3
set failtime 10
set recoverytime 10
set update-cascade-interface disable
set protocol ping