Ask n.yc: Can anyone recommend a good tutorial for iptables?

I found this in my bookmarks, but I don't remember how helpful it was: <a href="http://iptables-tutorial.frozentux.net/iptables-tutorial.html" rel="nofollow">http://iptables-tutorial.frozentux.net/iptables-tutorial.htm...</a>

One of the Linux magazines (Linux+, I believe) has been running a series on using iptables for the last couple months...