FortiOS 6.0.3 Issues with Fortigate DHCP server and Cisco WAPs
I updated a Fortigate 81E to FortiOS 6.0.3. After doing so, the DHCP services to wireless devices connecting via Cisco WAPs broke. After a bit of wiresharking it appears that the way FortiOS processes the DHCP Offer packets has changed. In particular, the server seems to ignore the DCHP Discover's broadcast bit and sends out the DHCP Offer as a broadcast at the IP and MAC layers. This is different than what FortiOS 5.4.4 does. The difference is enough to impact my Cisco gear.
I've submitted a ticket along with explanation and wireshack captures to Tech Support but they've been strangely quiet about it.
Has anyone else noticed this behavior?