About the New Windows Firewall
One of the most significant changes in SP2 is in the Windows Firewall, formerly known as Internet Connection Firewall (ICF). The Windows Firewall is a stateful host firewall that blocks all unsolicited incoming traffic that doesn't correspond to a request by the workstation. The Windows Firewall does not block outbound traffic. In most of cases, services are able to communicate through the firewall—without any additional user action or configuration—because communication with the host is initiated (solicited) by Reflection. The response from the host is automatically allowed through the firewall because it is solicited traffic. But some services do receive unsolicited incoming traffic, and you'll need to configure the Windows Firewall to allow traffic for these components: You can configure the firewall to allow traffic in two ways: by adding the port or by adding the program to the exception list.
Why open ports?
When troubleshooting a program that doesn't work, you may find that in order for the program to be able to communicate on the Internet, a particular port on the firewall needs to be opened. Here's how to open a port if you're using XP's built-in Internet Connection Firewall (ICF):
How to Open
- Click Start | My Network Places and select View Network Connections, or right click My Network Places on the desktop and select Properties
- Right click the connection you use to connect to the Internet and select Properties
- Click the Advanced tab, then Settings
- Click Add
- In the Description box, enter a name to identify the port you are opening and the application that will use it
- In the box labeled "Name or IP address of the computer hosting this service on your network," enter 127.0.0.1 (this identifies your local computer)
- In the boxes labeled "External port" and "Internal port," enter the port number for the application you want to use (this depends on the specific application and is usually the same number)
- Select TCP or UDP, depending on which protocol is used by the application
Here is a small tip
Once the Windows Firewall in enabled, traffic on port 445 will be blocked and this is the port used for remote administration with programs such as the Event Viewer and Computer Management consoles. If you need to perform remote administration, you can open port 445 using the following command:
Netsh firewall set portopening TCP 445 ENABLE