From owner-freebsd-net@FreeBSD.ORG Sun Feb 1 00:18:59 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 64F1ED41 for ; Sun, 1 Feb 2015 00:18:59 +0000 (UTC) Received: from mail-pa0-x22c.google.com (mail-pa0-x22c.google.com [IPv6:2607:f8b0:400e:c03::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2F9E0D62 for ; Sun, 1 Feb 2015 00:18:59 +0000 (UTC) Received: by mail-pa0-f44.google.com with SMTP id rd3so67005904pab.3 for ; Sat, 31 Jan 2015 16:18:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=KZNN63lYRHfLCpR8hiPtkg4jGecC7BN9UdJQksodfbk=; b=ZPXuiTi2aPyhivbe6zgoNCTxk00D/6cGXNtU3AYnk4VDuGUjAkp6d+LeVE5jCFM7dr +aTUWY8qOIekamI0xGAmfKyTkb5e5i2JWMFmv5pTlONVzpxzZrPwcPfyVx+YlK8Ewj58 BZ2ZzILU3AXPvrxeTiDSasCxFdqp3zAgnRnrrl2UyFctl8CAuFBMjrEwkjIn+0BzTjUC BazaO9Ry7R6tI13A7tTbcU6vGP2M+lsKrcU1Q2INwTf212C1qIdwTulmlAI2FZOCaUq2 eU0JqTJDYZQLiZ+1enu7Z/yOvWkyAUM6PXEzkiwQtsi9bIN8izhhxDoTTEHe23jutxxH ZsvQ== MIME-Version: 1.0 X-Received: by 10.68.242.163 with SMTP id wr3mr19036882pbc.159.1422749938615; Sat, 31 Jan 2015 16:18:58 -0800 (PST) Sender: kob6558@gmail.com Received: by 10.67.22.231 with HTTP; Sat, 31 Jan 2015 16:18:58 -0800 (PST) In-Reply-To: References: <54C918D2.7090805@FreeBSD.org> Date: Sat, 31 Jan 2015 16:18:58 -0800 X-Google-Sender-Auth: hhZOz-6SAg8SO5NB8dukbbrQydo Message-ID: Subject: Re: Problems with DNSSEC -- answer in fragmented UDP doesn't work From: Kevin Oberman To: David DeSimone Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: "freebsd-net@freebsd.org" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Feb 2015 00:18:59 -0000 On Fri, Jan 30, 2015 at 10:11 PM, David DeSimone wrote: > Kevin Oberman wrote: > > > > For ipfw you need something like "allow ip from any to me frag". If you > > want to restrict this to DNS, restrict it to dst-port 53. > > Unfortunately, UDP fragments only contain the port number in the very > first fragment. So you will not be able to forward the later fragments > based on port number. You can only see the Src/Dest IP and Protocol number > in the fragment. > > -- > David DeSimone == fox@verio.net == Network Admin > You are, of course, correct. Specifying a destination port is meaningless. If you accept any fragments, you accept all of them. -- Kevin Oberman, Network Engineer, Retired E-mail: rkoberman@gmail.com