Fortigate Can't Connect To Fortimanager

(2026-02-18)

Problem:

Fortigate shows as "down" in Fortimanager, but isn't. Most of the time said Fortigate is behind some kind of NAT'ing firewall itself.

Solution:

This magic chicken waving worked for me.

diagnose debug reset
diagnose debug application fgfmd -1

diagnose debug cli 8
diagnose debug console timestamp enable
diagnose debug enable

config sys central-management
set fmg FMG-FQDN-or-IP
end

fnsysctl killall fgfmd

This usually persuades the firewall to start talking to the Fortimanager again. If it doesn't, there should be some gratuitous output that might point you in the right direction.