With Windows XP, Microsoft introduced a firewall included with its operating system. Providing a firewall with XP was an attempt to assist users in securing their computer from Internet security threats. Not using a firewall allows all ports to be open to intruders. The firewall allows both TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) to be opened for specific ports. Applications that communicate to users or to a central computer over the Internet require one or more ports to be opened in the firewall.
Steps to to Configure Ports on Windows XP Firewall
• Click on the "Start" button on the Windows menu bar. Select "Network Connections"
• Right-click on the connection you use for the Internet and select "Properties."
• Click on the "Advanced" tab of the window and click on the button labeled "Settings."
• Click on the button labeled "Add" to open the form to enter the new port information.
• Enter a description of the what the port is used for in the text field labeled "Description."
• Enter "127.0.0.1" in the field labeled "Name or IP Address of the Computer Hosting the Service."
• Enter the port number required by the application in the text boxes labeled "External" and "Internal."
• Select the desired protocol for this port of either "UDP" or "TCP" and then click on the button labeled "OK."