Re: [Idr] WG LC on draft-ietf-idr-large-community-03.txt (10/17/2016 to 10/31/2016)

Brian Dickson <brian.peter.dickson@gmail.com> Fri, 21 October 2016 01:48 UTC

Return-Path: <brian.peter.dickson@gmail.com>
X-Original-To: idr@ietfa.amsl.com
Delivered-To: idr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 659A01294B1 for <idr@ietfa.amsl.com>; Thu, 20 Oct 2016 18:48:48 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.699
X-Spam-Level:
X-Spam-Status: No, score=-2.699 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 U3vnpRF_lNA4 for <idr@ietfa.amsl.com>; Thu, 20 Oct 2016 18:48:45 -0700 (PDT)
Received: from mail-lf0-x22b.google.com (mail-lf0-x22b.google.com [IPv6:2a00:1450:4010:c07::22b]) (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 EE14F1293F2 for <idr@ietf.org>; Thu, 20 Oct 2016 18:48:44 -0700 (PDT)
Received: by mail-lf0-x22b.google.com with SMTP id l131so110926615lfl.2 for <idr@ietf.org>; Thu, 20 Oct 2016 18:48:44 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=Yx2fceWQ1/wLLn1kcQ644YhUOeciGkFdZ8q+8/EO2ig=; b=wllyWJAGfeQeRk1HOpCV80JdMpyOb4WeR+jVzXKireOY0RM+sePlVANNWTliKtObzS r1I/C/sJ//YtlXpZkJV6pUF1FwPl4ei6/O5QUnU779V6urnjxy1hBbYENFbcmLjBpVse t9iNRQzlrWvI9EmbA5kX6HM1lKukyMn9zXW0jQXAACBi/HN5K7R/ZfEQ4ajrYrNVE6DP FXym9uHt6+j/F4ViB7sWncoubfZSmOrLZTMYQ2CxSeitzrJqgPKPpM3HjvDOARGZOAxN PLRC60aLtaY1cPEtctQ/w3KMryDIn88indlkFqu7hFkPFIkD4pSdeYdkhWMuUPSM3yUB vQIQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=Yx2fceWQ1/wLLn1kcQ644YhUOeciGkFdZ8q+8/EO2ig=; b=O+HLohiWSzkMyncQiHL7C3XdNcwLx7S6wpiQYm3E/WLDKfd7kcJUKX4rTYCidqhV5O qbS7q7TzmRhYkRElDEUz+GKZit70F78ij4G1OmN08qDprvV+utRye2RJMbyfH/9RZ//1 rDU299oUUArFXWbJC04RHczoYhw8uU9Gz+9sO6pkaBL/wGwwxRAwxUoZcDffAspksEhW SpnyqbdMvz3jDR3NeHlLPfqqjojdb5PlxNcEvLccgmR/OdEZL0GCNtyZM6rsT/8FVFqT 3ezFfqcVpenpxKdKLzykxTtif6gmaM9HWQWpyJjdDww0FJpn9YBjUHuqxMsIP4TUETzM VNaA==
X-Gm-Message-State: AA6/9RndjdCPQlXwTeR9FUOcJKSs0i+cpchy0jjBbEBrsu+DANDukI3TYWyfEaklbUgHHNW3fFEuoDMsXvMvAA==
X-Received: by 10.28.222.70 with SMTP id v67mr692787wmg.84.1477014523044; Thu, 20 Oct 2016 18:48:43 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.28.203.207 with HTTP; Thu, 20 Oct 2016 18:48:41 -0700 (PDT)
In-Reply-To: <dc81002a2d93480eb0aeec334b35b5c8@XCH-ALN-014.cisco.com>
References: <01f301d228b4$e3319ef0$a994dcd0$@ndzh.com> <20161017215134.GA464@pfrc.org> <20161018190851.GC15392@shrubbery.net> <20161018191521.GT95811@Vurt.local> <9EFC9BAA-F917-4C70-A139-1F69CAECF9C0@pfrc.org> <20161020215938.GE1074@Vurt.local> <adb00bcd7b8e45db857eae7019c646fc@XCH-ALN-014.cisco.com> <20161020225004.GG1074@Vurt.local> <a141faafa05845a1af6417a73aa2f361@XCH-ALN-014.cisco.com> <2894c1eb263143cc8129ec8e381957dc@XCH-ALN-014.cisco.com> <CAH1iCir1YYibzvcLuEwBHtyNL6b_Wbxp6k4=_DFOe20a4OFpZg@mail.gmail.com> <dc81002a2d93480eb0aeec334b35b5c8@XCH-ALN-014.cisco.com>
From: Brian Dickson <brian.peter.dickson@gmail.com>
Date: Thu, 20 Oct 2016 18:48:41 -0700
Message-ID: <CAH1iCirDeoT+nhm+a8X0r5W8fB3perqzQRF2VdvXRP2hbdMujg@mail.gmail.com>
To: "Jakob Heitz (jheitz)" <jheitz@cisco.com>
Content-Type: multipart/alternative; boundary=001a114b103cf96871053f563df7
Archived-At: <https://mailarchive.ietf.org/arch/msg/idr/Cl4w7WUQHVyOX5ZJpa_NLgMOI20>
Cc: heasley <heas@shrubbery.net>, IETF IDR WG <idr@ietf.org>, Sue Hares <shares@ndzh.com>
Subject: Re: [Idr] WG LC on draft-ietf-idr-large-community-03.txt (10/17/2016 to 10/31/2016)
X-BeenThere: idr@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Inter-Domain Routing <idr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/idr>, <mailto:idr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/idr/>
List-Post: <mailto:idr@ietf.org>
List-Help: <mailto:idr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/idr>, <mailto:idr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 21 Oct 2016 01:48:48 -0000

On Thu, Oct 20, 2016 at 5:46 PM, Jakob Heitz (jheitz) <jheitz@cisco.com>;
wrote:

> I do understand that the community may travel several AS hops.
>
> That's why I wrote
>
>
>
>   A Large Community that
>
>   is *intended to be sent to multiple ASes* SHOULD contain an ASN
>
>   in the Global Administrator field. The ASN SHOULD be one that
>
>   is assigned to the entity
>
>   that defines the meaning of the rest of the Large Community.
>
>
>
> I also understand that this is not the only case and that communities
>
> are often used within an AS only. We MUST NOT restrict that use.
>
>
>

Agreed.

I think the tweak to your wording along the lines of:
"...within an AS and across AS boundaries, ANY values will be allowed."
That removes the notion of adjacent, as well as whether B is sender or
recipient.

Entity is fine.

Thanks,
Brian


> Also, even though AS B defines the community that has GA=B, AS B
>
> is not always the intended recipient. Many ISPs use communities
>
> to signal properties of routes that they send to their customers.
>
> In that case, AS B is the sender, not the recipient.
>
>
>
> I wrote "entity" and not "AS", because someone may create only a
>
> single BGP AS, but be assigned many ASNs. That someone is entitled
>
> to use any of her assigned ASNs, not just the one in use by her AS.
>
>
>
>
>
> Thanks,
>
> Jakob.
>
>
>
> *From:* Brian Dickson [mailto:brian.peter.dickson@gmail.com]
> *Sent:* Thursday, October 20, 2016 5:28 PM
> *To:* Jakob Heitz (jheitz) <jheitz@cisco.com>;
> *Cc:* Job Snijders <job@ntt.net>;; heasley <heas@shrubbery.net>;; IETF IDR
> WG <idr@ietf.org>;; Sue Hares <shares@ndzh.com>;
>
> *Subject:* Re: [Idr] WG LC on draft-ietf-idr-large-community-03.txt
> (10/17/2016 to 10/31/2016)
>
>
>
>
>
>
>
> On Thu, Oct 20, 2016 at 4:46 PM, Jakob Heitz (jheitz) <jheitz@cisco.com>;
> wrote:
>
> Perhaps, we should add in an operations section that we should not and
> will not go any further.
> In particular, within an AS and between adjacent BGP neighbors, ANY values
> will be allowed.
> The only requirement is that sender and receiver have the same
> understanding of the contents,
> but no RFC is required to say this.
>
>
>
> Jakob,
>
>
>
> I think you still don't understand the purpose or the mechanics of
> communities, as what you say makes almost no sense.
>
>
>
> The reason "large" needs to be an optional, transitive attribute, is that
> the intended party, whose ASN
>
> is in the Global Administrator field, is not necessarily the first or
> second party (the one setting the community,
>
> or the one that is the BGP peer of the first party).
>
>
>
> The community may travel an arbitrary number of AS hops before it is
> received by the ASN in question (global admin).
>
> That ASN is the one who is the (ultimate) intended recipient (of the
> community), and whose interprets the latter 8 octets
>
> of the community, using whatever logic he/she wishes. (The prefix will
> probably propagate much further, but we
>
> are only concerned about the ASN that is the global administrator of the
> community.)
>
>
>
> This is NOT limited to within an AS, nor to adjacent BGP peers.
>
>
>
> As such, the intermediate AS hops will receive the prefix with the
> attached Large Community, but will
>
> not have any understanding of the contents. They are expected to pass them
> along, as this is the
>
> necessary part of communities' functioning.
>
>
>
> A -> X -> Y -> Z -> B are the Autonomous Systems passing the prefix.
>
> A sets the community. The community is B:something:something.
>
> B interprets the community.
>
> X, Y, and Z, pass it along without acting on it.
>
>
>
> I'm sorry to raise a fuss, but since you are involved in editing the I-D,
> it would put my mind at ease to hear you say
>
> that you understand the above.
>
>
>
> Putting text into this document, if you don't understand the above, may be
> harmful to the document,
>
> and to operator folks who are trying to get the bugs out of the document
> before it advances.
>
>
>
> Sincerely,
>
> Brian
>
>
>
>
>
> Thanks,
> Jakob.
>
>
>
> > -----Original Message-----
> > From: Idr [mailto:idr-bounces@ietf.org] On Behalf Of Jakob Heitz
> (jheitz)
> > Sent: Thursday, October 20, 2016 4:06 PM
> > To: Job Snijders <job@ntt.net>;
> > Cc: heasley <heas@shrubbery.net>;; Sue Hares <shares@ndzh.com>;; IETF IDR
> WG <idr@ietf.org>;
> > Subject: Re: [Idr] WG LC on draft-ietf-idr-large-community-03.txt
> (10/17/2016 to 10/31/2016)
> >
> > Evidently, it wasn't clear. Now it is.
> >
> > Thanks,
> > Jakob.
> >
> >
> > > -----Original Message-----
> > > From: Job Snijders [mailto:job@ntt.net]
> > > Sent: Thursday, October 20, 2016 3:50 PM
> > > To: Jakob Heitz (jheitz) <jheitz@cisco.com>;
> > > Cc: Jeffrey Haas <jhaas@pfrc.org>;; heasley <heas@shrubbery.net>;; IETF
> IDR WG <idr@ietf.org>;; Sue Hares
> > > <shares@ndzh.com>;
> > > Subject: Re: [Idr] WG LC on draft-ietf-idr-large-community-03.txt
> (10/17/2016 to 10/31/2016)
> > >
> > > Hi Jakob,
> > >
> > > I am not sure what issue this replacement resolves. With the
> replacement
> > > text in the document I feel I have more questions than answers.
> > >
> > > Usually a community is intended to be sent to one AS to trigger an
> > > action, and to multiple ASes if the community is of informative nature.
> > > We know we can attach multiple Large BGP Communities to a route,
> because
> > > of the variable length of the attribute.
> > >
> > > In an earlier response I pointed at text that addresses this specific
> > > feature already in the current text: https://mailarchive.ietf.org/
> arch/msg/idr/_QULjIUDaBB4JqDR8IXuIYkAVJw
> > >
> > > Kind regards,
> > >
> > > Job
> > >
> > >
> > > On Thu, Oct 20, 2016 at 10:13:41PM +0000, Jakob Heitz (jheitz) wrote:
> > > > In addition, to deal with the values for the GA field, we will
> replace
> > > >
> > > >    The Global Administrator field is intended to allow different
> > > >    Autonomous Systems to define Large BGP Communities without
> collision.
> > > >
> > > > with
> > > >
> > > >   A Large Community that is intended to be sent to multiple ASes
> > > >   SHOULD contain an ASN in the Global Administrator field. The ASN
> > > >   SHOULD be one that is assigned to the entity that defines the
> > > >   meaning of the rest of the Large Community.  This allows a route to
> > > >   carry multiple Large Communities, the meaning of each being defined
> > > >   by different independent entities.
> >
> > _______________________________________________
> > Idr mailing list
> > Idr@ietf.org
> > https://www.ietf.org/mailman/listinfo/idr
>
> _______________________________________________
> Idr mailing list
> Idr@ietf.org
> https://www.ietf.org/mailman/listinfo/idr
>
>
>