[dns-operations] History Question - Who first created/used DNS RBL?

Paul Vixie paul at vix.com
Thu Jan 31 06:11:50 UTC 2008

> Who first created/used DNS RBL for a policy enforcement/security tool?

eric ziegast, then of vixie enterprises, on "Fri, 03 Oct 1997 15:22:39 -0700",
while doing major cleanups to our sendmail.cf file to get rid of a thousand
lines of custom database lookup and move as much as he could into DNS, sort of
overshot the goal.  he didn't like that we rejected all traffic from RBL'd
networks, when rejecting only e-mail would do.  so since he was teaching our
sendmail how to do DNS lookups for mail routing information, he awk'd the
gated.conf file into a DNS zone, and wrote a 4-line sendmail ruleset to look
stuff up.  thus was born rbl.maps.vix.com, and a thousand powerpoint preso's
and HOWTO files and an e-mail reputation industry.

> I'm collecting information on the various whitepapers on the technique and
> noticed a lot of "invented here" approaches. So I was just wondering where
> the genesis of the technique emerged.  For me DNS RBL is like BGP RBL.
> Someone taught it to me back in 1992.
> Anyone remember back that far?

even though i had by that time co-written a book about sendmail, i never would
have imagined that it could do the kind of lookups eric made it do for the RBL.
all i knew how to do at the time was edit a gated.conf file to install routes
covering known-spammy networks.

rbl.maps.vix.com STILL gets queried, by the way.

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