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

Toerless Eckert <tte@cs.fau.de> Mon, 07 March 2022 12:39 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 702E13A0C9E for <int-area@ietfa.amsl.com>; Mon, 7 Mar 2022 04:39:49 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.66
X-Spam-Level:
X-Spam-Status: No, score=-1.66 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.248, RCVD_IN_DNSWL_BLOCKED=0.001, 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 TlpNCV_RSWZf for <int-area@ietfa.amsl.com>; Mon, 7 Mar 2022 04:39:45 -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 13D353A0DE3 for <Int-area@ietf.org>; Mon, 7 Mar 2022 04:39:44 -0800 (PST)
Received: from faui48e.informatik.uni-erlangen.de (faui48e.informatik.uni-erlangen.de [131.188.34.51]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by faui40.informatik.uni-erlangen.de (Postfix) with ESMTPS id 5808D549A2C; Mon, 7 Mar 2022 13:39:39 +0100 (CET)
Received: by faui48e.informatik.uni-erlangen.de (Postfix, from userid 10463) id 403C64EA854; Mon, 7 Mar 2022 13:39:39 +0100 (CET)
Date: Mon, 07 Mar 2022 13:39:39 +0100
From: Toerless Eckert <tte@cs.fau.de>
To: Brian E Carpenter <brian.e.carpenter@gmail.com>
Cc: Dino Farinacci <farinacci@gmail.com>, "Int-area@ietf.org" <Int-area@ietf.org>, Dirk Trossen <dirk.trossen=40huawei.com@dmarc.ietf.org>
Message-ID: <YiX9C8g5d2WGThhH@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> <YiH6iHwv+U9QFA06@faui48e.informatik.uni-erlangen.de> <499a3364-7ea5-4268-cce3-43f010f36a72@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <499a3364-7ea5-4268-cce3-43f010f36a72@gmail.com>
Archived-At: <https://mailarchive.ietf.org/arch/msg/int-area/YmP-HozQXyGeaZxHC0QuyGw12WM>
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: Mon, 07 Mar 2022 12:39:50 -0000

Thanks, Brian. Looks like a good reference. Alas a longer read ;-)

Definitions seem to be agreeable. Except that "node" is overloaded across
different RFCs.  We used it instead of router/switch in ANIMA. I guess
i would now use  "logical entity" for what rfc6115 calls logical node.

Cheers
    Toerless

On Sat, Mar 05, 2022 at 08:57:36AM +1300, Brian E Carpenter wrote:
> Toerless,
> 
> I believe the closest we ever got to agreed definitions was in the
> IRTF RFC 6115:
> 
>    6.   A "locator" is a structured topology-dependent name that is not
>         used for node identification and is not a path.  Two related
>         meanings are current, depending on the class of things being
>         named:
> 
>         1.  The topology-dependent name of a node's interface.
> 
>         2.  The topology-dependent name of a single subnetwork OR
>             topology-dependent name of a group of related subnetworks
>             that share a single aggregate.  An IP routing prefix is a
>             current example of the latter.
> 
>    7.   An "identifier" is a topology-independent name for a logical
>         node.  Depending upon instantiation, a "logical node" might be a
>         single physical device, a cluster of devices acting as a single
>         node, or a single virtual partition of a single physical device.
>         An OSI End System Identifier (ESID) is an example of an
>         identifier.  A Fully Qualified Domain Name (FQDN) that precisely
>         names one logical node is another example.  (Note well that not
>         all FQDNs meet this definition.)
> 
> Regards
>    Brian
> 
> On 05-Mar-22 00:39, Toerless Eckert wrote:
> > 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