Well, multiple gateways and policy routing DOES work with FortiOS 2.8, at least for MR5 (didn’t try with previous versions). But with the FortiOS 2.8 Admin Guide it doesn’t clear how you could actually do it.
We have 2 internet connections, both are with static IPs. When we were on 2.5 everything was clear and straightforward: one gateway is primary, where all traffic is forwarded to by default and second one is the secondary - to accept the traffic in case of primary gateway failure; both specified in a single route. Then with the help of policy routing you can force traffic to the secondary gateway when necessary.
With 2.8 you do not have an option with 2 gateways in a single route any longer. At first it seemed to be obvious how I would configure the box to achieve the same goal: 2 static routes with different metrics pointing to different gateways; the route with the lower metric would be the primary (or default) and with higher metric – the secondary. Then, again with policy routing you could reroute traffic depending on your needs. I guess, most of us did the same thing and we know the result…
After I spent some time trying to make it work I contacted Fortinet Support (they didn’t respond to my e-mail for 2 days, so eventually I had to call them). So here is my solution. To make it work with two gateways I had to configure 2 static routes. There are two important things here:
1. Both routes must have the same metric!
2. The primary (or default) route will be the one which is the second (lowest) in the list.
As to the policy routing, it works as usually – there are no surprises here.
There is only one little thing, which I am still concerned about: FortiGate interface associated with the secondary route does not respond to pings even if it is clearly enabled. Everything else seem (fingers crossed) to be working OK. I sent e-mail to Support with the question – so far there is no response (they became much slower in response – are very busy now

).
VA