The computer has over 65 thousand ports. The port is opened only if some program is using it. The port number is selected by the OS or running application. In some cases, the user may need to open a specific port.
Instructions
Step 1
The program needs a port to communicate with the network. Some programs work with standard ports, others are allocated by the operating system any free one. When using standard ports, they are hardcoded into the program's configuration. Therefore, in order to open a specific port, it must be specified in the settings of the program that should work with it.
Step 2
Do not confuse opening a port on your computer with allowing the firewall to open a port for connection. In the first case, we are talking about the actual opening of the port - that is, some program starts to use it. In the second, the port can be closed (that is, no program is using it), but when you try to open it, the firewall will not block the connection.
Step 3
You can see a list of ports open on your computer, which can be useful if you suspect that the system has been infected with Trojans. Click on the command line: "Start" - "All programs" - "Accessories" - "Command line". A black console window will appear, this is the command line. Enter the command netstat –aon and press Enter.
Step 4
In the list that appears, in the "Local address" column, you will see a list of ports open on your computer. The column "External address" contains addresses and ports on remote computers. The "Status" column shows the status of the connection. The last column, PID, will show you the process ids. They are useful if you want to know which program is opening a particular port.
Step 5
Type tasklist in the same window and press Enter again. A list of processes running on the system will appear. In the second column, right after the name of the processes, there are their identifiers, by which you can easily find the program that opened the port you are interested in.
Step 6
If you need to open a port in the standard Windows firewall, then this can also be done through the command line. For example, to open port 34567, type the command in the console: netsh firewall add portopening TCP 34567 system and press Enter. To close it again, enter the command: netsh firewall delete portopening TCP 34567. You can view the console and Windows firewall settings by entering the command: netsh firewall show config.
