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Date: Fri, 12 Dec 2003 07:26:28 -0600
From: "Jacques A. Vidrine" <nectar@FreeBSD.org>
To: Brett Glass <brett@lariat.org>
Message-ID: <20031212132628.GB19204@madman.celabo.org>
References: <200312120312.UAA10720@lariat.org>
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cc: net@freebsd.org
Subject: Re: Controlling ports used by natd
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On Thu, Dec 11, 2003 at 08:12:49PM -0700, Brett Glass wrote:
> Is there a way to control the range of ports to which FreeBSD's
> natd maps outgoing connections? I'm attempting to deal with a
> situation in which natd is (sometimes) changing outgoing UDP 
> packets' source port numbers to ones which are commonly used 
> by worms. Sometimes, a firewall at the destination blocks the
> packet; at other times, the response is blocked on the way
> back.
> 
> If it is possible to tell natd to avoid using ports that are
> firewalled, it ought to be possible to avoid this problem. But
> I can find no way to do this. Does one exist?

I suppose there is brute force.  Use an application like PortSentry to
bind the ports that you don't want to be used by natd.

Cheers,
-- 
Jacques Vidrine   NTT/Verio SME      FreeBSD UNIX       Heimdal
nectar@celabo.org jvidrine@verio.net nectar@freebsd.org nectar@kth.se