IETF Logo Mail Archive

Re: Why do we need to go with 128 bits address space ?

Carsten Bormann <cabo@tzi.org> Fri, 16 August 2019 05:59 UTC

Return-Path: <cabo@tzi.org>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 86E2A120033; Thu, 15 Aug 2019 22:59:59 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.198
X-Spam-Level:
X-Spam-Status: No, score=-4.198 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001] autolearn=unavailable autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OcerjqRiFNrd; Thu, 15 Aug 2019 22:59:57 -0700 (PDT)
Received: from gabriel-vm-2.zfn.uni-bremen.de (gabriel-vm-2.zfn.uni-bremen.de [134.102.50.17]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 2C9A712002E; Thu, 15 Aug 2019 22:59:57 -0700 (PDT)
Received: from [192.168.217.110] (p548DCCB9.dip0.t-ipconnect.de [84.141.204.185]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by gabriel-vm-2.zfn.uni-bremen.de (Postfix) with ESMTPSA id 468t2M0b6Fz10XP; Fri, 16 Aug 2019 07:59:55 +0200 (CEST)
Content-Type: text/plain; charset="utf-8"
Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\))
Subject: Re: Why do we need to go with 128 bits address space ?
From: Carsten Bormann <cabo@tzi.org>
In-Reply-To: <CAPTMOt+cGhBqHmT3yZVChv-PCMqxT-WPDcDdM3RuTc1TMfFeVg@mail.gmail.com>
Date: Fri, 16 Aug 2019 07:59:54 +0200
X-Mao-Original-Outgoing-Id: 587627993.246871-166770632f9ed542521a5e32abeda154
Content-Transfer-Encoding: quoted-printable
Message-Id: <A73D3F51-0C60-437A-AE8A-DF464F2042D4@tzi.org>
References: <CAPTMOt+cGhBqHmT3yZVChv-PCMqxT-WPDcDdM3RuTc1TMfFeVg@mail.gmail.com>
To: IETF Discuss <ietf@ietf.org>, irtf-discuss@irtf.org, 6man <6man@ietf.org>
X-Mailer: Apple Mail (2.3445.9.1)
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/EXW-369xTCXMP-E9Vlu8ze54Nfg>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 16 Aug 2019 06:00:00 -0000

> 64 bits

How quaint.  Everybody knows the right answer is 53.

(1) 53 dec is 35 hex.  Wins right away.

(2) 53 bits is all that can be expressed by a JavaScript integer [RFC7493], and routers are sure migrating from ASICs to JavaScript.

(3) the 32-bit Internet is not going away soon.  We all know a good compromise between 32 and 64 is 48.  Let’s add in 10 % for good measure, making it 52.8, and round up to the next bit, making it 53.

Grüße, Carsten

(Not sure that invoking ATM entirely works like Godwin’s law, but here’s my attempt to kill a useless thread.)

v2.23.0 | Report a Bug | By Email