I passed over this program as it is touted as protection for people who do P2P (file sharing). I don't do that, but that is a whole different story. While addressing one user's security concerns recently, I searched for an IP blocking and logging program. Peer Guardian may be just the thing.

A version for Windows Vista is in the works, for the moment you will need to download the version for your specific environment. I downloaded pg2-x64.exe and installed it on my Windows development System.

There are several types of block lists, many intended to keep the 'net cops out of your machine but there are also spyware and advertising sites. I installed a bunch, ran the updates, and fired up Firefox.

Instantly, I saw a list stream through the Peer Guardian window but nothing was getting blocked. After a couple of minutes I realised I visit sites that are low in advertising content (mainly Google ads).

So I headed over to http://slashdot.org. A bunch of DoubleClick calls were blocked and the download speed seemed improved. From there, I went to http://newsforge.com. More being blocked but some flash content from Akamai was getting through.

I tried out the custom block list feature and could not get Peer Guardian to let me at the starting and ending IP addresses. I saved an akamai entry anyway and dug up the file with wordpad. The format is trivial and I replaced the 0.0.0.0-0.0.0.0 with the IP range obtained from http://horace.ls.net/phpwhois-4.1.2/example.php?query=72.246.51.9&output... our trusty whois server. Remove the blanks in the IP list or Peer Guardian will ignore your entry. Later I found Peer Guardian was blocking the RSS feed for BBC (Latest Headlines in the Bookmars Toolbar in Firefox). Again I fired up the List Manager in Peer Guardia, created a new List GoodSites, added an entry for BBC (found by using whois on horace), saved it, edited the files goodsites.p2p to reflect the IP address range, saved the file, disabled and enabled Peer Guardian to generate a new IP cache file and I got my BBC Live Feed back.

Back on the 'net I hit http://cnn.com - it wouldn't load and http://msnbc.com - which was decimated but readable. I don't need sites laden with advertising so it doesn't matter to me. Your mileage may vary.

The original concern was that my system (or yours) might be leaking. After an hour of testing no outbound traffic was blocked meaning Peer Guardian does not think I nor my machine are visiting places we shouldn't. I started digging through the "History" and the list was rather long and in time order. If I wanted to check for bad permitted IP addresses, it would be handy if the list could be sorted by IP address instead of time. There is a very functional search tool so that if I knew what I was after, I could probably find it. But I am randomly trying to grok what this all means and I came up short. I suspect it might be fun to fire it up and let it run without surfing and see what my machine tries to do on its own.

If you are paranoid, and just because you are paranoid does not mean someone is not out to get you (thanks Fritz), this might be an important tool. It's small, turns off easily and the source code is open so foul play is unlikely (not the case with most advertised spyware programs).