Forum Discussion
Blocking TCP 3389 - issues?
There is a strong push here to block RDP over part of our network. MSDI uses 3389 for name resolution. What order does MSDI use the three available methods for name resolution - TCP 135 (NTLM), UDP 1...
Blocking 3389 reduce the visibility to rdp based attacks, however you can exclude https://learn.microsoft.com/en-us/defender-for-identity/exclusions
