Archive for mars, 2008

Putting the Spamhaus DROP list in FreeBSD’s ipfw

søndag, mars 16th, 2008

Are you aware of the Spamhaus DROP list? According to the ladies and gentlemen of Spamhaus:

DROP (Don’t Route Or Peer) is an advisory “drop all traffic” list, consisting of stolen ‘zombie’ netblocks and netblocks controlled entirely by professional spammers. DROP is a tiny sub-set of the SBL designed for use by firewalls and routing equipment.

So DROP is simply a short-ish list of CIDR numbers and Spamhaus SBL references, and that we can definitely use in our FreeBSD ipfw rules. There’s a couple of perl scripts in the DROP FAQ, but none of them is suitable for generating ipfw rules, so I went ahead and made my own script. Yup, a good old-fashioned shell script. I don’t speak perl (not very well, anyway), and a shell script can be made equally no-nonsense and portable in my opinion. I operate several internet-facing FreeBSD servers, and they all use this script to generate ipfw rules.