30th July 2002

The following is why I am a big fan of using either a router or some type of hardware firewall on your home network. From the Microsoft Knowledge Base: "When you start or shut down your Windows XP-based computer, the Internet Connection Firewall (ICF) does not filter or provide firewall services. During the startup or shutdown process, users can connect to your computer or to any program or service that may be available. Note that other than these two times, ICF works correctly. This issue occurs because during startup and shutdown, the user-mode service is not available. Because of this, the filter driver does not know which policy to enforce, and does not filter anything." Please note that this may not be an issue with other software firewall alternatives, such as ZoneAlarm or Tiny Personal Firewall.