Fortigate 60E internal switch blocks DHCP traffic etc.

[owiking]

Hi

We have a Fortigate 60E that we use for a VPN connection to our main site. On the local site we have a Windows 2016 DHCP server that will also act as a PXE boot server running SCCM.

When I connect the server to one of the internal switchports on the F60E and connects some client on the other internal ports, DHCP requests doesnt work, it is as if the firewall is blocking the DHCP broadcast. If I assign I static IP on one client, it can communicate with the server and to our main site through the VPN connection.

If i connect the server and the clients in another switch, leaving the F60E out, the DHCP works as it should.

I have been trying to find if the F60E somehow blocks traffic on the internal switch? All our rules says that we should allow all traffic.

Anyone got any ideas?

I have been looking around in the CLI and found some settings that I thought might help, but non have so far.

Ex. set intra-switch-policy implicit and also trying to allow broadcast traffic, 

F60E

Firmware v5.6.1 build1484 (GA)

Thanks.

/Olof