Minecraft Multiplayer Connection Issues Behind FortiGate Firewall

[barry_62]

Hi everyone,

I’m having an odd issue with Minecraft and FortiGate and wanted to see if anyone here has run into something similar. I read this thread https://community.fortinet.com/t5/Support-Forum/Unblock-certain-

game/m-p/390777/highlight/true and it reminded me of what I’m dealing with, but the solutions there didn’t quite fit my situation.

When I try to join certain Minecraft multiplayer servers (especially public ones), the connection either times out or I get disconnected after a few seconds. Singleplayer works fine, and some servers connect without any problem, which makes it confusing.

I checked basic settings like allowed ports and application control, and nothing obvious is being blocked. I’m wondering if FortiGate might be identifying some Minecraft traffic incorrectly or if there’s a specific profile or setting that usually causes issues with game traffic.

If anyone has experience running Minecraft behind FortiGate, I’d really appreciate hearing what worked for you or what I should check next.

Thanks in advance!

[ezhupa · Accepted solution]

Hello barry_62,

If you are the administrator of the FGT, I would suggest checking the Firewall Policy responsible for this traffic first.
If there are any sort of security profiles enabled there, I would check Security Logs for the particular security profiles e.g if you have Webfilter, check Web filter logs under Log & Report to check for any blocks.
As a test you can try to remove all security profiles and leave a simple FW policy without inspection in flow mode. 
This should resolve the issue, in case there is some sort of blocking by the FortiGate.