A situation may happen that your Internet traffic may start to “suddenly” “go away” somewhere. In this case, you should pay attention to the ports of the computer: see where which application and what is using - and correct the situation based on the information provided.
Instructions
Step 1
It happens that an application that uses the network for its work does not want to work in any way - in this case, it is also worth checking whether the port that the program uses for its work is open. In general, situations when you need to find out the list of open ports arise quite often. In order to view the list, you must use either third-party port scanners or a standard utility for Linux and Windows operating systems: netstat. It runs from the command line. So call the command line. This can be done in two ways: 1. "Start"> "Run …". And in the window that appears, enter "cmd" and press "Enter"; 2. Launch the command line "manually", that is, go to the "C: / WINDOWS / System32" folder and run the "cmd.exe" program from there.
Step 2
Now you need to run the "netstat" utility. To do this, enter in the command line that was launched in the first step, "netstat" and press "Enter".
For those who do not have enough of this information, they can study the capabilities of this utility by running it with the –h switch, that is, enter “netstat -h” in the command line. The most probable and common keys for launching: "netstat -b" - in this case, the utility will display not only open ports, but also the applications themselves that use these ports for their work; "Netstat 5". In the case of such a launch, information about open ports will be displayed with a time step of five seconds, that is, information will be updated every five seconds, and in order to stop displaying information with a given key, press the "Ctrl + C" key combination.
Step 3
Study the information. The open ports are displayed in the command prompt window. It will look like this: the command line will be divided into four parts, with the name of the protocol in the left column, the domain and the open port after the colon, in the third column, the external address, and in the fourth, the state.
