Need to check if Port 3389 is Open on My MAC (Ventura 13.5 OS)

Unless you are using 3rd party anti-virus software, Little Snitch, etc…, then as the client, you do not open specific numbered ports, you connect to remote specific numbered ports.

The mention of 3rd party software is because sometimes they block network connections.

With the current version of RDC installed, visit System Settings : Network : Firewall > [ Options… ]. Disable Block all incoming connections, and check if there is an entry just below it with Remote Desktop wanting to accept incoming connections. If a selector is present but red, change it to accept incoming connections. Or, click the + button to see if it will add RDC to this panel. Since RDC is advertising on port 3389, it should make the Windows Server connection for you provided it is properly configured. No need to perform a port scan even if you could.

You may want to enable Automatically allow downloaded signed software to receive incoming connections.

I don't use RDC and the above is essentially a WAG in hopes it works for you.

The hosting software is blocking my revisions to the preceding post. Ignore it. I just watched a YouTube video about installing RDC on macOS Ventura and setting up the configuration, connecting to a remote server account, and logging out of the remote server. Nothing mentioned about needing to know about port 3389 as the correct configuration leads to a successful session. What was not mentioned in the video was whether the Firewall was on or off, and whether if on, the block all connections was disabled in System Settings : Network : Firewall > [ Options… ] panel.

If you are trying to connect from a remote network, make sure port forwarding is properly configured in your local router to forward to to correct port on the correct computer on your local network.