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 From:  "Neil A. Hillard" <m0n0 at dana dot org dot uk>
 To:  m0n0wall at lists dot m0n0 dot ch
 Subject:  Re: [m0n0wall] Are TCP DNS queries possible?
 Date:  Tue, 13 Sep 2005 23:32:04 +0100

>That's for Windows/Exchange 2000.  It doesn't say it will fall back
>though, it says, "Request for Comments (RFC) 883 and the later RFCs
>prescribe that DNS servers be able to accept both TCP virtual circuits
>and UDP."
I couldn't see in that RFC where it stated that it MUST.  You should
note that that RFC was obsoleted by RFC1034 and RFC1035 in 1987 !!!

RFC1035 states:
> While virtual circuits can be used for any DNS activity, datagrams are
> preferred for queries due to their lower overhead and better
> performance.
Which is obviously why M$ chose TCP over UDP - nice, thanks Bill.


Neil A. Hillard                E-Mail:   neil at dana dot org dot uk
                               Web:      http://www.dana.org.uk/