There is such a situation that he does not want in any to run an application that uses a network for its operation - in this case, it is also worth checking if the port is open, which the program uses for its work. In General, situations when you need to find out the list of open ports are common. In order to see the list, you must use either third-party port scanners or standard utility for Linux and Windows: netstat. It runs from the command line. So open a command prompt. This can be done in two ways: 1. "Start" > "Run...". In the window that appears, enter "cmd" and press "Enter"; 2. To run the command line "manually", i.e. go to folder "C:\WINDOWS\System32" and run the program from there "cmd.exe".
Now you need to run the utility "netstat". To do this, type at the command line, which was launched in the first step, "netstat" and press "Enter".
For those who this little information, can explore the possibilities of this tool, run it with –h, that is, type in command prompt "netstat -h". The most probable and common keys to run: "netstat-b" - in this case the utility will display not only the open ports, but the apps that use these ports for its operation. "netstat 5". In the case of such starting information about the open ports will be displayed in increments of five seconds, the information will be updated every five seconds, and to stop the output of data with a given key, use the key combination "Ctrl+C".
Examine the information. In the command prompt window will display the open ports. It will look the following way: the command line will be divided into four parts, and in the left column will indicate the name of the Protocol in the second domain and after the colon is an open port, the third external address and the fourth state.