How to define open ports?

Now we will deal with the question of what open ports are. In this issue, it should be understood if Internet traffic begins to "suddenly go" into the unknown. First of all, you should see where, what program and what exactly it uses. Based on this information, you can correct the situation.

Network applications

There is a situation when the application does not want to work, which uses the network to launch it. If this is the case, it is worth checking whether the ports that the program uses for its own work are open. Situations when it is necessary to learn the list of open ports, take place quite often.

To view the list, you must use either third - party port scanners, or the standard utility of Windows and Linux operating systems: netstat. It starts from the usual command line. First we call the command line. This can be achieved in two ways. As for the first option, go to the "Start" menu to "Run".

In the appeared window enter "cmd", then press "Enter". Another method is to run the necessary command line "with your own hands", that is, by going to the "System32" folder, use the program "cmd.exe".

Netstat

To find out which ports are open, in the next step we run the utility "netstat". To this end, enter "netstat" on the command line that you started earlier, and then press "Enter".

Those users who do not have enough information can access the capabilities of this utility by running it with the -h special key, in other words, try typing "netstat -h" into the command line. If you use the "netstat -b" key, the utility will show the open ports, as well as applications that use these ports for their own work.

There is one more useful key called netstat 5. If you use it, you will see not only open ports, but also the possibility of streaming information updates, new data will be displayed every 5 seconds. To stop the appearance of information with the specified key, you must use the keyboard shortcut "Ctrl + C".

Study of information received

The command window will show the open ports. This will look like this: the immediate command line is divided into 4 parts. The left column will display the name of the protocol, the second - the domain, and after the colon itself the open port, the third part - the external address, the fourth - the state.

Opening ports in Windows

Next, we'll look at how to open the Windows port . Perform the operation of opening ports on Windows 7 and Vista users can use the standard tools of the operating system itself without involving special software from third-party developers.

Press the "Start" button to bring up the main menu of the system, go to "Control Panel", in order to initiate the procedure of opening ports in Windows-Firewall.

Specify the item "Security", go to the "Windows Firewall" section. We select an item called "Advanced Options", which places the left part of the application window in itself. After that, enter the administrator password. It must be entered in the corresponding field after the authorization window appears.

Reveal the link, which refers to the permission to start the program through the Windows Firewall, and select the section about the rules of incoming connections. Specify the item called "Create rule", run the "Add port" function to perform the operation of opening the specified port. Click the "Next" button, enter a name that allows you to associate the specified open port.

For this purpose, the corresponding field "Name" is provided. Enter the number of the selected port in the corresponding field "Port", press the "Next" button. Specify the desired protocol (it can be TCP or UDP) in the next dialog box, which is dedicated to ports and protocols. Apply the checkbox for "Allow connection" by going to the next "Actions" window.

The final stage

Apply the checkboxes for all the fields in the next dialog box named "Profile", click the "Finish" button to apply the selected changes. Click the button called "Change Area" to select the number of computers that have permission to use the selected port. Specify the desired value.

We repeat the above procedures for each of the ports that are to be opened. We reboot the computer to apply the selected changes. It should be remembered that the described algorithm of actions will allow to open ports only in the firewall of a personal computer, but it is not connected in any way with the permissions of a certain Internet connection provider.

To solve such problems, you need to contact the representative of your provider company directly. During the Internet connection, the system allocates to the programs working with the network the ports through which the reception is received and also the data is sent. Ports can be not only open, but also closed.