Re: [Int-area] Continuing the addressing discussion: what is an address anyway?

Toerless Eckert <tte@cs.fau.de> Fri, 04 March 2022 11:40 UTC

Return-Path: <eckert@i4.informatik.uni-erlangen.de>
X-Original-To: int-area@ietfa.amsl.com
Delivered-To: int-area@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 992B43A10EB for <int-area@ietfa.amsl.com>; Fri, 4 Mar 2022 03:40:02 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.661
X-Spam-Level:
X-Spam-Status: No, score=-1.661 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.248, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, URIBL_BLOCKED=0.001] autolearn=no 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 gj9QistCrdlH for <int-area@ietfa.amsl.com>; Fri, 4 Mar 2022 03:39:58 -0800 (PST)
Received: from faui40.informatik.uni-erlangen.de (faui40.informatik.uni-erlangen.de [131.188.34.40]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 53A5E3A130F for <Int-area@ietf.org>; Fri, 4 Mar 2022 03:39:58 -0800 (PST)
Received: from faui48e.informatik.uni-erlangen.de (faui48e.informatik.uni-erlangen.de [IPv6:2001:638:a000:4134::ffff:51]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by faui40.informatik.uni-erlangen.de (Postfix) with ESMTPS id A3C64549FC7; Fri, 4 Mar 2022 12:39:52 +0100 (CET)
Received: by faui48e.informatik.uni-erlangen.de (Postfix, from userid 10463) id 9AE6A4EA80B; Fri, 4 Mar 2022 12:39:52 +0100 (CET)
Date: Fri, 04 Mar 2022 12:39:52 +0100
From: Toerless Eckert <tte@cs.fau.de>
To: Dino Farinacci <farinacci@gmail.com>
Cc: Eliot Lear <lear@lear.ch>, "Int-area@ietf.org" <Int-area@ietf.org>, Dirk Trossen <dirk.trossen=40huawei.com@dmarc.ietf.org>
Message-ID: <YiH6iHwv+U9QFA06@faui48e.informatik.uni-erlangen.de>
References: <57c643c667d94a77b9917bb17dc142a5@huawei.com> <7de0956f-3fde-1543-405b-b635f6e69362@lear.ch> <Yh5M18z2/YVfpW7i@faui48e.informatik.uni-erlangen.de> <A771FFF8-43A8-4D84-8B6E-A3E7AF96644E@gmail.com> <YiBhOKIK9bMqwx0a@faui48e.informatik.uni-erlangen.de> <385CF477-C876-482F-ADFE-DAAD6CA7BAEC@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <385CF477-C876-482F-ADFE-DAAD6CA7BAEC@gmail.com>
Archived-At: <https://mailarchive.ietf.org/arch/msg/int-area/ZRD0Y4kMPQWKpJc30QxIQDf-j2g>
Subject: Re: [Int-area] Continuing the addressing discussion: what is an address anyway?
X-BeenThere: int-area@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: IETF Internet Area WG Mailing List <int-area.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/int-area>, <mailto:int-area-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/int-area/>
List-Post: <mailto:int-area@ietf.org>
List-Help: <mailto:int-area-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/int-area>, <mailto:int-area-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 04 Mar 2022 11:40:03 -0000

On Thu, Mar 03, 2022 at 09:28:23AM -0800, Dino Farinacci wrote:
> > of its address structure helps the underlay to locate the entity (xTR) that the
> > address is assigned to (xTR). So the name 'locator' is 'just' a good
> > name for what LISP calls/uses the address for, not for how the under
> > itself would maybe call the address or use the address for. 
> 
> Well the locator you put in an outer header destination address is called/used/assign to whatever the rules of the underlay are. If the underlay is ethernet, then its a 6-byte address where the high-order 3 bytes is an organizational ID, just to cite an example.

Indeed.

I have not seen an answer to the question i posed earlier in the thread:
 whether and if so what general (not technology specific) definition of locator
and identifier the IETF may have. But i have seen a lot of confusion about
it and people shying away from using these terms.

If (as i think) we do not have a commonly applicable definition of locator/identifier 
(beyond its use in indivdual technologies like LISP), then i think this is because
folks who tried to apply these terms (incorrectly) may have failed to
see the difference between what an address is and what someone (like an
application) calls it (/uses it for). In that respect the reference to
the White Knight in IEN19 is very helpful to remember.

Cheers
    Toerless

> Dino

-- 
---
tte@cs.fau.de