Technical Tip: Microsoft RDP freeze and cause FortiGate slow when trying to access to an Microsoft Windows server

This article describes when remote access to Microsoft Windows is hosted behind the FortiGate, causes the FortiGate to become unresponsive during the RDP session Scope.

When trying to perform remote access to the Microsoft Windows hosted behind the FortiGate, the client will be noticed were trying to access via UDP port 3389 instead of TCP 3389 via FortiGate FortiView sessions.

The client are found 'spamming' huge UDP 3389 traffic, and cause the Microsoft RDP and FortiGate freezes/slow

The solution is to either:

1)Create a new FortiGate firewall policy to deny Microsoft RDP via UDP port 3389.

2)  Follow the solution provided by third party (credit).
https://www.mustbegeek.com/rdp-connection-freezes-in-windows-10/
(*Take notes that this third party website is not manage by Fortinet).

Related link.

Technical Tip: Windows RDP connection dropped:
https://community.fortinet.com/t5/FortiGate/Technical-Tip-Windows-RDP-connection-dropped/ta-p/197443?externalID=FD40006