How can I check what a port is doing?

However, it is port congestion that is one of the primary reasons for incorrect network operation: Freezes, slowdowns, lags. Although each program uses its own port, sometimes several programs intersect in one of them, and a kind of “plug” occurs. We'll tell you how to detect the notorious "plug" below. The most common port occupancy problem occurs with port number 80 - one of the most basic routes for many programs.

So, we need our favorite command line. It is called through the "Run" menu, which, in turn, is called hotkey combination Windows+R. In the "Run" menu enter cmd - we are on the command line.

We need a team here netstat -ano (we write it this way, with a space before the hyphen and without a space without it!).

We will see many local addresses. they all look something like xxx.xxx.x.xxx:PORT. Yes, the port is written after the colon.

Select a specific port, drag your finger to the last column and find out the process ID. Remember the ID number. This completes the work with the command line.

Launch the task manager (everyone knows how to call it: Ctrl+Alt+Del or Ctrl+Shift+ESC).

If you are using a Windows 8/8.1 system, then the IDs are initially registered in the “Details” tab. If your OS is Windows 7 or lower, then first go to the “View” menu, select “Select Columns” and check the box next to PID.

After confirming the changes, we will see a column with ID. We look for the ID number from the command line, and thereby easily find out which process, and therefore which program uses this or that port. So, now you know how to check ports for blockages, and this is a very useful skill in the face of a large number of programs running on the Internet. Good luck!