Subject: Re: grow: [GROW] Agenda Items for Vienna

From: Olivier Bonaventure <[email-masked]>
Date: 03 Jun 2003 08:34:24 +0200

David,
> 
> 	Its about time to start thinking about agenda items for
> 	the Vienna ITEF. Please forward any GROW agenda items
> 	you might have to me.

Last year, Bruno Quoitin and I wrote a survey of the utilization of the
BGP community attribute based on analysis of RPSL specifications in the
RIPE whois database and on routing tables collected by RouteViews and
the RIPE RIS project. This draft, draft-quoitin-bgp-comm-survey-00.txt,
has now expired.

Since the publication of RFC1998, the BGP Community attribute has been
used for various purposes that were not envisionned initially. We intend
to describe the most common usages of this attribute in a new draft that
should be ready within a few weeks and could serve as a BCP document to
describe those utilizations of the community attribute.

This draft might fit in the GROW WG.

Best regards,

Olivier
-- 
CSE Dept. UCL, Belgium - http://www.info.ucl.ac.be/people/OBO/

____________________________________________________________
Web Archive:     http://darkwing.uoregon.edu/~llynch/grow/

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From: "Sean McCreary" <[email-masked]>
Date: Mon, 09 Jun 2003 22:25:30 -0600

Olivier Bonaventure <[email-masked]> wrote:
[...]
>describe those utilizations of the community attribute.

At NANOG28 there were questions raised during Phil Smith's tutorial that
might have been answered by your draft.  Have you resubmitted it, or can
you make a copy available elsewhere?
--
Sean McCreary                                                 [email-masked]
____________________________________________________________
Web Archive:     http://darkwing.uoregon.edu/~llynch/grow/

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From: Olivier Bonaventure <[email-masked]>
Date: 10 Jun 2003 09:19:35 +0200

Sean, 

> you make a copy available elsewhere?

We are finalizing the draft and it will be ready within one or two
weeks. The old version (March 2002) is still available from 
http://www.info.ucl.ac.be/people/OBO/biblio.html
The new version will contain more tutorial information. If you send some
of the questions raised during the NANOG tutorial, we could try to
address them in our draft.

Best regards,

Olivier Bonaventure

---

From: Philip Smith <[email-masked]>
Date: Tue, 10 Jun 2003 18:26:47 +1000

>address them in our draft.

Olivier, the main thing people were asking me about, certainly after I gave 
the multihoming tutorial, was about the lack of documentation and 
coordination of community values in general use. I think folks were just 
looking for guidelines and examples of what they could use, what their 
peers and upstreams were using, and how to generally take advantage of the 
community attribute.

I'd promised for at least two years or so now to put some text around the 
Tiscali/Nacamar values (as now used by BT Ignite, for example), but thus 
far it has remained a promise. :-( Would love to see your new draft, 
especially if it goes some way to helping folks make greater use of 
communities within their own networks, and between themselves and their 
immediate peers.

philip

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From: Jeffrey Haas <[email-masked]>
Date: Tue, 10 Jun 2003 09:38:37 -0400

Philip,

> peers and upstreams were using, and how to generally take advantage of the 

One of the motivations for the redistribution extended communities was
to take commonly implemented communities that affect redistribution
policy and make it easy for vendors to implement knobs that did the
common stuff. :-)

-- 
Jeff Haas 
NextHop Technologies

---

From: Jeffrey Haas <[email-masked]>
Date: Tue, 10 Jun 2003 12:19:16 -0400

On Tue, Jun 10, 2003 at 09:11:13AM -0700, john heasley wrote:
> hmm, do you really want vendors to do 'the common stuff', peer prepending
> for example?  i may have taken your comment too literally, but the social
> aspects of peering policy make such a proposition disagreable.

The most common knobs that customers are usually offered are roughly:
o prepend this route
o don't announce this route
o don't export this route outside of your AS.

Other knobs that are commonly offered are:
o prefer this route
o deprefer this route

The first set of things are what the redistribution draft is trying
to accomplish - provide a way for a provider to get these knobs without
needing to be in route-map hell.  The fact that you can implement
these communities softly without vendor cooperation is handy.

To address some of your possible issue with this, the knobs are
explicitly noted as something you may want to be able to shut off
with some neighbors.

Also note that I used "peering" in the "neighbor" sense, not the
financial sense.

> as far as i am concerned, the greatest and possibly only value of extended
> communities are the non-transitive bit and the ability to represent a 4
> octet AS.

Thats a biggy.  The fact that its structured has proved to be a boon
for a lot of IETF WG's that want to distribute stuff into BGP that
needs to be tagged.

> the remainder seems to be over complication of what has been a
> simple unsigned 4 octet value. :)

Arguably, while a boon, its a pain to have all this 
extended community parsing code.

---

From: john heasley <[email-masked]>
Date: Tue, 10 Jun 2003 09:11:13 -0700

as far as i am concerned, the greatest and possibly only value of extended
communities are the non-transitive bit and the ability to represent a 4
octet AS.  the remainder seems to be over complication of what has been a
simple unsigned 4 octet value. :)

---

From: john heasley <[email-masked]>
Date: Tue, 10 Jun 2003 09:55:09 -0700

> needing to be in route-map hell.  The fact that you can implement

_route-maps_ are hell.  perhaps applying duct tape in the wrong place?

> explicitly noted as something you may want to be able to shut off

better be a MUST have .... :)  always seems easier when the vendor isnt
involved.

> extended community parsing code.

yep

---

From: Olivier Bonaventure <[email-masked]>
Date: 19 Jun 2003 12:03:54 +0200

Philip,
> peers and upstreams were using, and how to generally take advantage of the 

The draft has been sent to the IETF secretariat. It will appear within
several days on the IETF annoucements list. In the mean time, you can
retrieve it from
http://www.info.ucl.ac.be/people/OBO/papers/draft-bq-bgp-communities-00.txt

Comments are of course more than welcome

Best regards,

Olivier Bonaventure