Re: [OPSAWG] [GROW] WG LC for draft-ietf-opsawg-ipfix-bgp-community

Hi,

With the hat of the developer of a open-source / free IPFIX collector (*, **), I would like to express two opposite concerns with regards to this draft - loosely related to the very details of the draft itself.

One concern is that this looks a very isolated effort, ie. why communities and not as-path? I remember the story of this draft, it comes from field needs and that is in short the answer to the cherry-picking.

The second concern, the one going the opposite direction than the previous one, is that in future it could be tempting for somebody to repeat the story of this draft and add support for as-paths and/or other BGP attributes in IPFIX: here i see a mix-up among the original intent to report on data plane information with the reporting on control-plane (BGP) information: in other words, is (potentially) encapsulating (all) BGP attributes for every sampled packet/flow a valid idea? For example, is not BGP/BMP peering at the IPFIX collector itself much more efficient instead of moving control-plane info over and over again? At this propo, the motivation that roughly 20 years ago it was decided to make source and destination ASNs part of NetFlow v5 (and few years later BGP next-hop was added as part of NetFlow v9) is a bit weak, IMO; maybe there is more to it, and i’d be happy to hear about it. 

On the details of the draft itself instead, i reckon the effort to support Extended and Large communities (comment from Ignas Bagdonas last year); i also followed the discussion with PJ Aitken about segmentation/fragmentation of potentially long communities list and i seem to reckon there is no good (simple, straightforward) solution to address that.

Paolo

(*) http://www.pmacct.net/
(**) https://github.com/pmacct/pmacct

> On 23 Jan 2018, at 02:10, Tianran Zhou <zhoutianran@huawei.com> wrote:
> 
> Dear GROW WG,
> 
> The OPSAWG started a 2 week WG LC for a BGP related draft:
> https://tools.ietf.org/html/draft-ietf-opsawg-ipfix-bgp-community-04
> 
> It would be really helpful and appreciated if you can read it.
> Could you please provide comments (if any) and copy to opsawg@ietf.org?
> 
> Cheers,
> Tianran, as OPSAWG co-chair
> 
> 
> -----Original Message-----
> From: OPSAWG [mailto:opsawg-bounces@ietf.org] On Behalf Of Tianran Zhou
> Sent: Thursday, January 18, 2018 11:07 AM
> To: opsawg@ietf.org
> Cc: opsawg-chairs@ietf.org
> Subject: [OPSAWG] WG LC for draft-ietf-opsawg-ipfix-bgp-community
> 
> Hi WG,
> 
> The authors of draft-ietf-opsawg-ipfix-bgp-community have posted the latest drafts to the mailing list, and believe that the document is ready for LC.
> 
> This starts a 2 week WG LC on
> https://tools.ietf.org/html/draft-ietf-opsawg-ipfix-bgp-community-04
> 
> Please read the above draft and send any issues, comments, or corrections to this mailing list. 
> All supports and concerns are welcome and helpful for the authors.
> 
> We are also looking for a document shepherd, best with operator background, to help the following procedures.  
> 
> The WG LC will close on Feb 1, 2018.
> Authors please indicate whether you are aware of any IPR for the draft.
> 
> Thanks,
> Tianran, as OPSAWG co-chair
> 
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