The computers connected to the network are controlled by logical interfaces called network protocols. For data exchange on the Internet, TCP / IP protocols are used.
Instructions
Step 1
The Internet Protocol (IP) defines the delivery of data from one host to another. At the same time, it does not guarantee the accuracy of delivery: during transmission, packets may be lost or received in a different order than they were sent. The Transmission Control Protocol - TCP is responsible for accuracy. TCP establishes a connection, controls the sending and receiving of packets, duplicates its actions in the event that a response to a request is not received or packets are lost. It is important to understand that TCP establishes packet exchange not just between nodes, but between software applications. A network port is a convention, a number between 1 and 65535, that indicates to which application the packet is assigned.
Step 2
You can find out which processes are using ports on your computer using standard Windows tools. From the Start menu, click Run and type cmd into the Command Prompt. Confirm with OK. In a console window, type netstat -a -n -o.
Step 3
The PID column contains the process number, the “Local address” column contains the IP address of your computer and, separated by a colon, the port number that is occupied by the corresponding process. The "external address" is the IP and port number of the remote node with which some application is running.
Step 4
In the console window, type the tasklist command. It will list all PID code applications that are running on the computer. This way you will find out which process is occupying any port on your computer.
Step 5
You can get this information differently: start the "Task Manager" from the command line by typing taskmgr, or by pressing the Ctrl + Alt + Delete keys. In the PID column find the number of the process you are interested in, in the Image Name column - the name of the corresponding application or service. If the PID is not displayed in the Manager window, go to the "View" item of the main menu and select the "Select columns" option. Check the box next to Process ID (PID).
