PeerGuardian is a tool used to better secure your file sharing experience. Its primary function is to block harmful ip addresses from connecting to your system. PeerGuardian comes with an extensive list of harmful ip addresses which can be updated regularly. Upon installation you will notice a simple to use interface. In addition, PeerGuardian allows you to keep a log of all your incoming connections, allowing you to backtrack and narrow down the search for a particular ip address or range of IP addresses.

How PeerGuardian Works

PeerGuardian is an open source IP filter that is designed to block the IP addresses of certain organizations and corporations that may wish to harm a users privacy while using the Internet and peer-to-peer networks. PeerGuardian 2 requires no driver installation, yet blocks IP addresses at a far higher speed than was previously available – never above 1% CPU on most test systems. On Windows 2000 and greater PeerGuardian 2 blocks at a kernel level, acting against every protocol used within the windows system. On Windows 98 or Me it blocks TCP only (due to technical reasons, kernel blocking in 98/ME is not feasible) with the same high performance of the Windows 2000 version.

PeerGuardian blocks IP addresses based upon a list of IP addresses collected by many methods. By default, PeerGuardian 2 collects IP addresses from the website. is a website designed to allow users to interactively manage and block the IP addresses of certain organisations and companies. Founded in early 2005 by, it is intended to be a platform agnostic database that utilises published open formats. is still under construction, and more detail about how to use the database to submit new ranges, and report bad ranges will be added to a later version of this manual.

What’s New In PeerGuardian?

PeerGuardian 2 is now totally automatic. You do not need to install a driver, simply run the program without any visits to the control panel. The new start-up wizard makes things easier than ever. Also kernel level blocking make the system far more efficient and powerful than any previous version.

How safe is PeerGuardian, really?

Well, it is accurate in the sense that it blocks everything on your blocklist. It is impossible to know all the addresses to block, so while it will increase your safety to a good extent, it can never be perfect. Some features are:

  • Detects and closes connections from specified IP ranges.
  • Blocks out known P2P harmful IP addresses by default.
  • Allows you to manually close connections.
  • Customized lists from to ensure the latest ranges
Review by Jared Moya

PeerGuardian has an average rating 2.9 out of 5 based on 88 user ratings.