Re: [BEHAVE] (no subject)

Mark Andrews <marka@isc.org> Thu, 27 June 2013 14:14 UTC

Return-Path: <marka@isc.org>
X-Original-To: behave@ietfa.amsl.com
Delivered-To: behave@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id DE6E821F9B81 for <behave@ietfa.amsl.com>; Thu, 27 Jun 2013 07:14:53 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.435
X-Spam-Level:
X-Spam-Status: No, score=-2.435 tagged_above=-999 required=5 tests=[AWL=0.164, BAYES_00=-2.599]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tAzVGDh3yRTL for <behave@ietfa.amsl.com>; Thu, 27 Jun 2013 07:14:49 -0700 (PDT)
Received: from mx.pao1.isc.org (mx.pao1.isc.org [IPv6:2001:4f8:0:2::2b]) by ietfa.amsl.com (Postfix) with ESMTP id 7C30D21F9D6A for <behave@ietf.org>; Thu, 27 Jun 2013 07:14:49 -0700 (PDT)
Received: from mx.pao1.isc.org (localhost [127.0.0.1]) by mx.pao1.isc.org (Postfix) with ESMTP id E9664C9465; Thu, 27 Jun 2013 14:14:40 +0000 (UTC) (envelope-from marka@isc.org)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isc.org; s=dkim2012; t=1372342489; bh=MYQIr2WNVO2roDyQxbOgJ8SisFeknSbIXG0b0HH2NLU=; h=To:Cc:From:References:Subject:In-reply-to:Date; b=HWlP8mFdwV2x/nsD1Fu2N133NDOxmPMWkeQx+Z9lB+8kh3u1Qu83wlYeCxhS8kFyr uS/wM1fO/ns5FS/l20iuGtZUwVk82Rk+Bf3Xd9fOn8R9Ia4t/BJQvxE0KwB2HRX2yv QOZ8fviESXbx6NNkmOooaf5A95v7lF0TGMJlualU=
Received: from zmx1.isc.org (zmx1.isc.org [149.20.0.20]) by mx.pao1.isc.org (Postfix) with ESMTP; Thu, 27 Jun 2013 14:14:40 +0000 (UTC) (envelope-from marka@isc.org)
Received: from localhost (localhost [127.0.0.1]) by zmx1.isc.org (Postfix) with ESMTP id C76BD16004A; Thu, 27 Jun 2013 14:15:57 +0000 (UTC)
Received: from zmx1.isc.org ([127.0.0.1]) by localhost (zmx1.isc.org [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 1jbobOKIbGSB; Thu, 27 Jun 2013 14:15:57 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1]) by zmx1.isc.org (Postfix) with ESMTP id 7832E16009F; Thu, 27 Jun 2013 14:15:57 +0000 (UTC)
X-Virus-Scanned: amavisd-new at zmx1.isc.org
Received: from zmx1.isc.org ([127.0.0.1]) by localhost (zmx1.isc.org [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 2ugA6OuCeAFN; Thu, 27 Jun 2013 14:15:57 +0000 (UTC)
Received: from drugs.dv.isc.org (c211-30-172-21.carlnfd1.nsw.optusnet.com.au [211.30.172.21]) by zmx1.isc.org (Postfix) with ESMTPSA id 2750816004A; Thu, 27 Jun 2013 14:15:57 +0000 (UTC)
Received: from drugs.dv.isc.org (localhost [IPv6:::1]) by drugs.dv.isc.org (Postfix) with ESMTP id 3B0BD365EA62; Fri, 28 Jun 2013 00:14:34 +1000 (EST)
To: Simon Perreault <simon.perreault@viagenie.ca>
From: Mark Andrews <marka@isc.org>
References: <CB1B483277FEC94E9B58357040EE5D02325A6E93@xmb-rcd-x15.cisco.com> <2f7dce8264c8a9a72640629502a44295@cacaoweb.org> <51C1681A.5030909@viagenie.ca> <f8741fad1af1cee094de9c59408b7425@cacaoweb.org> <51C40374.8080403@viagenie.ca> <21e25b7ae1501228a67656b2fa4bc009@cacaoweb.org> <51CAA20F.4070307@viagenie.ca> <7f35bf30538732e3953bd33bcab7a791@cacaoweb.org> <51CC444C.1030507@viagenie.ca>
In-reply-to: Your message of "Thu, 27 Jun 2013 15:55:24 +0200." <51CC444C.1030507@viagenie.ca>
Date: Fri, 28 Jun 2013 00:14:34 +1000
Message-Id: <20130627141434.3B0BD365EA62@drugs.dv.isc.org>
X-DCC--Metrics: post.isc.org; whitelist
Cc: behave@ietf.org, ivan@cacaoweb.org
Subject: Re: [BEHAVE] (no subject)
X-BeenThere: behave@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: mailing list of BEHAVE IETF WG <behave.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/behave>, <mailto:behave-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/behave>
List-Post: <mailto:behave@ietf.org>
List-Help: <mailto:behave-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/behave>, <mailto:behave-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 27 Jun 2013 14:14:54 -0000

In message <51CC444C.1030507@viagenie.ca>ca>, Simon Perreault writes:
> Le 2013-06-27 15:44, ivan c a crit :
> >> I still haven't seen any explanation why the following excerpts do not
> >> apply.
> >>
> >> RFC 4787:
> >>
> >>      REQ-3:  A NAT MUST NOT have a "Port assignment" behavior of "Port
> >>         overloading".
> >>
> >> RFC 5382:
> >>
> >>      REQ-7:  A NAT MUST NOT have a "Port assignment" behavior of "Port
> >>         overloading" for TCP.
> >
> > Because some NATs would like to do port overloading, which is in
> > contradiction with these requirements.
> 
> "Would like to" is not a valid reason. We need technical arguments.
> 
> > See section 4. of
> > http://tools.ietf.org/html/draft-ietf-behave-requirements-update-00 .
> > You're mentioned as an author on this draft by the way.
> 
> I'm not disagreeing with myself. I am only observing that this 
> discussion still has not yielded any good technical argument that we 
> could add to our draft.
> 
> I have suggested that one condition where port overloading could be used 
> is when the NAT knows that it will not disrupt the application protocol. 
> For example, the protocols running on TCP port 80 and UDP port 53 (HTTP 
> and DNS) are purely client-server and therefore would not be affected by 
> port overloading. Allowing NATs to do port overloading for those ports 
> only would probably solve the scalability problem since they account for 
> a large portion of the traffic.

And overloading DNS could potentially defeat the port randomisation
done by the server even though nameservers do port overloading
themselves to send traffic out a large set of ports choosen at
random and reselected from at random.

> Do we really need anything more complex?
>
> > In this post I explain why port overloading can be somewhat desirable:
> > http://www.ietf.org/mail-archive/web/behave/current/msg10896.html
> > I make the same point across a large number of my posts.
> 
> We know that port overloading is desirable for a number of reasons.
> 
> What we need to argue is why the undesirable effects of port overloading 
> do not apply or can be ignored.
> 
> Simon
> _______________________________________________
> Behave mailing list
> Behave@ietf.org
> https://www.ietf.org/mailman/listinfo/behave

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org