About Port 3389 and Windows Operating System outgoing question


I know that source port is usually random , but I want to ask is, is it normal that「Windows Operating System」pick up the port 3389 as a source port and destination port 80 to connect to internet? even port 3389 should be used for Remote desktop services, does it possible be used for random source port in normal situation?

And what does「Windows Operating System」exactly mean?

Block it.

“Windows operation system” is a “place holder” in comodo. Especially when unrequested ingoing traffic is blocked (like it should).
Dont allow “place holders” (ingoing/outgoing)

Make sure that you dont allow INgoing traffic which would appear like what you described.

To avoid questions from the firewall about unrequested ingoing traffic, use stealth port wizard setting 3.

Thanks for reply.
But the situation happened because I blocked source port 3389, so I think I should not block source port because it’s random number port.

Hi Uolioka,

You are right, source ports are randomly chosen. If you want to have peace of mind with Remote Desktop, you can disable it in the Windows services.