As with every software product, even the latest and greatest releases have some known glitches. That’s one of the reasons why you should review the release notes as part of the upgrade process.
But even then you might face a not-yet-documented issue. You’ll find some notable examples below.
FortiAPs won’t connect anymore (6.2.1)
Some customers have reported, that their FortiAPs won’t connect anymore after upgrading to FortiOS 6.2.1. Fortinet has confirmed that this is a know issue only when using trusted hosts to restrict the administrative access to the FortiGate.
The official workaround is to add the FortiAP’s IP or subnet as an additional trusted host entry on one of the admin users:
config system admin edit "adminuser" set trusthostx 10.33.33.3 255.255.255.255 <-- IP Address of the FortiAP next end
RADIUS Server behind VPN-Tunnel not working (6.2.1)
When using a RADIUS server behind an IPsec-tunnel, you most likely had to configure the source-ip in the radius configuration (normally to the internal address of the firewall). A bug in FortiOS 6.2.1 prevents this from working. As a workaround you’ll have to use an ip address owned by the outgoing interface.
config user radius edit "nps-server" set source-ip "192.168.101.99" <-- IP Address of the outgoing (IPsec)interface next end