Date: Wed, 9 Jul 2008 12:57:24 +0200 From: Mel <fbsd.questions@rachie.is-a-geek.net> To: freebsd-questions@freebsd.org Subject: Re: ports Message-ID: <200807091257.24627.fbsd.questions@rachie.is-a-geek.net> In-Reply-To: <DCE5DED7-40E2-406A-BB9D-1E5851811752@mac.com> References: <4873927E.3050307@godfur.com> <200807082004.25873.fbsd.questions@rachie.is-a-geek.net> <DCE5DED7-40E2-406A-BB9D-1E5851811752@mac.com>
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On Tuesday 08 July 2008 23:07:58 Chuck Swiger wrote:
> On Jul 8, 2008, at 11:04 AM, Mel wrote:
> > On Tuesday 08 July 2008 19:07:02 Matthew Seaman wrote:
> >> You can configure named to always send packets using a
> >> fixed port number (which can be helpful for firewalling)
> >
> > Purely outof interest, which (useful) firewall/nat rules cannot be
> > made with
> > dest port 53, that can be made with source port 53. Not talking
> > syntax,
> > but "business logically".
>
> Please note that using the same port for answering queries makes it
> vastly easier for somebody to spoof your DNS traffic. Unless you are
> one of the handful using DNSSEC, that is.
That's exactly why I asked. I don't see a reason to use a fixed source port,
since you can always make rules (even for bandwidth shaping) based on
destination port only. The only difference you'll able to account for
is "resolver clients querying directly to the internet installed on the
machine with your DNS server" vs the DNS server itself. IMO, that distinction
is not worth the risk or even important in any accounting/bandwidth shaping
scheme.
But I may have overlooked a valid scenario.
--
Mel
Problem with today's modular software: they start with the modules
and never get to the software part.
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