Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 29 Jan 2000 21:30:58 +0100
From:      Poul-Henning Kamp <phk@critter.freebsd.dk>
To:        sthaug@nethelp.no
Cc:        igor@physics.uiuc.edu, mccord@zytek.com, fbsd-security@ursine.com, freebsd-security@FreeBSD.ORG
Subject:   Re: Continual DNS requests from mysterious IP 
Message-ID:  <14538.949177858@critter.freebsd.dk>
In-Reply-To: Your message of "Sat, 29 Jan 2000 21:23:17 %2B0100." <2806.949177397@verdi.nethelp.no> 

next in thread | previous in thread | raw e-mail | index | archive | help
In message <2806.949177397@verdi.nethelp.no>, sthaug@nethelp.no writes:
>> However, the second method seems to provide more desired (?) result:
>> If you try to send an nslookup request about an outside domain
>> to the server from an outside host, it will respond as "query refused".
>> In the first case (using "allow-recursion"), the server will not
>> refuse the query, but rather will respond with the root-servers information.
>
>This is on purpose. The idea of the "allow-recursion" option is to limit
>the amount of work that a disallowed client can ask from your server. This
>means that it will either return a referral, or an answer from its cache.
>But it will *not* perform any new queries on behalf of a disallowed client.
>
>The amount of work to return a "query refused" is about the same as that 
>of returning a referral or an answer from the cache.

Yes, but "query refused" might have the advantage of signalling
the other end to reconfigure.

--
Poul-Henning Kamp             FreeBSD coreteam member
phk@FreeBSD.ORG               "Real hackers run -current on their laptop."
FreeBSD -- It will take a long time before progress goes too far!


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?14538.949177858>