nanog mailing list archives

Re: DNS deluge for x.p.ctrc.cc


From: Chris Adams <cmadams () hiwaay net>
Date: Fri, 24 Feb 2006 18:58:12 -0600


Once upon a time, Rob Thomas <robt () cymru com> said:
Limit recursion to trusted netblocks and customers.  Do not permit
your name servers to provide recursion for the world.  If you do,
you will contribute to one of these attacks.

One thing to note: we've discovered that on some common DSL routers, the
internal DNS caching server is on by default and answers requests on the
outside IP address.  IIRC some even do it when configured for NAT.

So, even when you disable outside recursion, things you may not think of
on the inside of your network may still allow outside DNS recursion.

-- 
Chris Adams <cmadams () hiwaay net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.


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