What is Windows Firewall?

Windows firewall is a software firewall present by default from Windows-based operating systems starting from Windows XP SP2 and onwards.

The Windows firewall is a packet filtering firewall. The Windows Firewall was also known as the Internet Connection Firewall (ICF) until its release as the Windows Firewall in 2004.

Previously until 2004, the Internet connection firewall used to be disabled by default because of backward compatibility issues.

But since there was an increased attack of worms and Trojans across the later part of 2003 and early part of 2004, Microsoft decided to give ICF a new look and launch it as Windows Firewall with more features.

By default Windows Firewall is enabled for each connection type, whether a wired connection or a wireless connection of VPN.

Windows Firewall also came with several additions and improvements in the group policy front, enabling administrators to configure Windows Firewall settings through the Active Directory group policy editor, which can be helpful for company-wide deployments.

The Windows firewall also provides logging facilities through which administrators can monitor the connection that originated from the Internet and came into the company network.

Windows Firewall in XP SP2 was not capable of blocking the outbound connection but was only able to control the inbound links. Starting with Windows Vista, outgoing connections can also be controlled using Windows Firewall.

Windows 7 and Windows 2008 also come with advanced Windows Firewall features. IPv6 is also supported in Windows Firewall. IPSec is now fully integrated, and hence connections can be denied or allowed based on the certificates or Kerberos authentication.

The advanced firewall features of Windows also include the ability to specify rules based on ports and IP addresses of connection and the service names. There is no need to select the full path for the service to create any Windows Firewall rule.