Re: [Idr] Transport Instance BGP

Zhuangshunwan <> Wed, 29 July 2020 10:09 UTC

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From: Zhuangshunwan <>
To: Robert Raszuk <>, Greg Skinner <>
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Thread-Topic: [Idr] Transport Instance BGP
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Date: Wed, 29 Jul 2020 10:09:23 +0000
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Subject: Re: [Idr] Transport Instance BGP
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Hi Robert,

When you mentioned BGP multi-session, I wondered what the drawbacks of this solution were that it was abandoned?


From: Idr [] On Behalf Of Robert Raszuk
Sent: Wednesday, July 29, 2020 5:06 PM
To: Greg Skinner <>
Subject: [Idr] Transport Instance BGP

Hi Greg,

Many thx for your comments. I do agree with all of them and if there is interest in IDR to proceed all of your points will be addressed.

Just a note on the first point you made ...

The proposal was shelved due to claims being made at and around Stockholm IETF that all we need is working BGP multi sessions to demux specific AFI/SAFI to a different session or different process within the box.

Well 10 years after I have not seen this to happen in *any* implementation.

Moreover in the mean time I see the proposals like BGP-LS which were promised during WG processing and LC to be deployed separately from Routing BGP (ex: dedicated RRs) in real deployments running on the same session and on the same platforms (RRs) where LSDB is fighting for processing resources with IP routes.

So here when we are discussing just using BGP as a transport because:

a) it is there
b) it takes everything (well used to till today :)
c) it is loop free distribution

my point of mentioning use of ti-bgp proposal (btw second choice if you go back to the note - first being JSON format and CURL for this type of distributions) was to at least decouple it hard from IP routing.

Many thx,

On Wed, Jul 29, 2020 at 3:06 AM Greg Skinner <<>> wrote:
(I limited the recipients in my response in order to (hopefully) focus on the IDR-specific topics covered in the quoted text.)

Regarding draft-raszuk-ti-bgp-01, if IDR has an interest in pursuing it again, I have some concerns:

  *   There were several issues raised<> during the IDR WG meeting during IETF 75 that should be addressed, IMO.
  *   I found some other issues in the draft that weren’t brought up during that meeting.  For example, in Section 5.5<>.5>, it is stated that "On the network side all today's BGP messages are send with IP precedence value of Internetwork Control of 110000, which is used for high-priority routing traffic.”  Is this true, even for open-source BGP implementations?  I looked at the source code for three implementations (Bird, FRR, and OpenBGPD), and was only able to confirm this for IPv4 OpenBGPD messages.
  *   One of the normative references, RFC 5226<>26>, has been obsoleted by RFC 8126<>26>.
  *   Several of the informative references have expired.
  *   The draft would require numerous editorial changes due to errors in spelling, grammar, etc.

Regards, Greg