Wifi Clients Connect But Can't Get DHCP Lease

(2019-04-17)

Problem

Wifi clients connect but can't get DHCP lease from either the Fortigate or from a DHCP server on the sofware-switch-connected network. Affects WPA2-Personal and WPA2-Enterprise secured SSIDs at the same time.

Solution

Immediately:

fw-foo # execute wireless-controller restart-acd
This operation will reboot wireless controller daemon!
Do you want to continue? (y/n)y


fw-foo #

Longer term, upgrading to 5.6.x seems to make the problem go away (or at least make fewer people complain about it on the internet).

Discussion

This problem appears to manifest mostly on 5.4.x, but I've seen a few people complaining about it on 5.6.x as well.