nanog mailing list archives

Re: DNS Blocking


From: Duane Wessels <cee4 () packet-pushers com>
Date: Thu, 19 Aug 2004 14:09:54 -0600 (MDT)


danm () prime gushi org ("Dan Mahoney, System Admin") writes:

What I was basically asking for was a "silently drop queries for X-domain"
option.  But one doesn't exist in bind.

take a look at www.as112.net to see what happens to queries for
10.in-addr.arpa and its brothers.  you can easily set up a zone

There weren't rfc1918.

Doesn't matter.  But in order for this trick to work:

  - The things sending you queries must be able to receive your
    replies.  I believe you said that source addresses are spoofed,
    so this may not be the case.

  - The things sending you queries must be smart enough to follow
    the NS referral in the response.

If I wanted to silently drop DNS queries based on the query name,
I might use FreeBSD's divert socket and a Perl script to examine
the queries.  Not sure well that would scale though.

Duane W.


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