I came across two great plugins – WP-Blacklister and IP Filter for WordPress. The first lists all the IP addresses for all the spam comments that a blog gets. The spam is identified by Akismet, I grab the IP addresses and then put them into TextWrangler. I sort the lines, find the really obnoxious networks, the ones with the same three octets over and over again, so something like 5.5.5.1 and 5.5.5.2, and 5.5.5.3, these, depending on how they resolve in an IP lookup get a block, either 5.5.5.* or 5.5.*.* or 5.*.*.*. From the left to the right there you block off more and more of the network. The more *’s in the block, the more stations are simply thrown off.

And then there is IP Filter plugin, I assemble a list of naughty IP’s and then fill in the details for this plugin. If an incoming IP address matches any of my blocks, they get no content and a short blurb stating that their network was either a source of spam, malware, or otherwise is unwanted traffic. I applied this list to all my blogs and I had spam comment rates which were about 30 per hour go to zero.

I will be creating a new page on my blog that lists these bad networks and IP addresses. Feel free to get this plugin and enter these blocks for yourself if you wish. I’ll be updating it as I find more spam or Limit Logon Attempt Plugin lockouts.

There is a wee part of me that is toying around with blocking the 141.218 subnet. We’ll see. 🙂