Fortinet and additional router

[MrAitch]

Hello,

About 18 months ago, we upgraded the school network, I insisted that we had Fortinet in to run our web filtering and firewall, but our IT guy (long gone) had to have a microtik router to manage the network and wireless AP, I don't know why, but it was a must have. I agreed as long as it worked with the fortinet and I didn't have to worry about it. Having used Fortinet before I know that it just works well, particularly in school environments

Roll on 12 months, IT guy has exited stage left (can't even begin to list the chaos that was uncovered), new IT guy comes in, and lots of things unravel, the main one being that the fortinet 200E was never set up. It has just sat there unusued for a year or more.

The suppliers have been in trying to make it play nice with the Mikrotik router but so far they have failed, my blood pressure has risen and that is about it.

My understanding at the moment is that we have several VLANS set up in school - students, teachers, admin staff, wifi. The Mikrotik runs all this, including the wifi AP.

The supplier and my IT guy cannot get the Fortigate and the Mikrotik to play nicely together. 

My first question is it possible to have the mikrotik running all the network login details etc and the Fortigate just managing the filtering/firewall side of things? That is all I really care about.

If it is possible any suggestions as to how it should be set up? So far everything they have done has blocked traffic on the network.

At one point it looked hopeful as they said it was communicating out the way, but nothing at all was coming back in. 

I am not living in the most proactive part of the world when it comes to problem solving, often the solution being it can't be done, rather than losing face and saying we don't know. 

Any thoughts would be appreciated so that I can go armed to the next shrugging shoulders meeting later this week.