TCP is one of the standards for the exchange of information between computers. In operating systems, a firewall or firewall is responsible for enforcing protocols and communicating through ports. This is the program that determines the state of the data exchange area, that is, the port. Using rules, you can allow or deny the exchange of information through a specific port.
Instructions
Step 1
Open the Start menu in the lower left corner of your desktop. Select "Control Panel" and launch the "Firewall" icon. If you have Activity Category View enabled, click the System and Security link. When the settings page opens, click on "Firewall" to open the program window. This applies to the Windows 7 operating system.
Step 2
Click on the "Advanced Options" link in the column on the left side of the page. If the User Account Control window opens, confirm your actions and enter the administrator password.
Step 3
Click in the left part of the window the line "Rules for incoming connections". A list of applicable rules and associated applications appears. Click on the "Create rule" caption, it is located in the upper right corner of the window. The dialog of the wizard for creating firewall rules will open.
Step 4
Check the box next to "For port" and click "Next". On the next page, leave the TCP Protocol checked at the top, and at the bottom, enter the port number you want to block access to. Then click the Next button.
Step 5
Check the box "Block connection" and click the inscription "Next". On the next screen, check all three boxes: domain, private, public - so that the created rule will be effective for all types of connections. Click Next to go to the last setup page.
Step 6
Give the rule you just created, such as Port 77, so you can easily find it when needed. You can add a description if required. Click the Finish button. The rule for an inbound connection was successfully created.
Step 7
Repeat all steps from the third to the sixth points if you want to block outgoing connections and completely close the tcp port. The only difference is that you need to click on "Rules for Outbound Connection". Close all settings windows and restart your computer. After that, the rule will take effect.
