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

2018-02-27 Thread Thomas.Graf
Hi Zhenqiang and the coauthors,

First of all I have to congratulate to this draft. I share the opinion that BGP 
communities are a very powerful information element. Correlated to the 
forwarding plane it gives a more detailed and granular view of the network 
usage then AS numbers or paths.

Looking from a MPLS VPN network provider perspective, which currently doing 
flow aggregation at the collector with BGP VPNv4/6 peerings to MPLS PE routers 
and encode inventory data into BGP communities, I have to agree with Paolo's 
opinion that this draft might not go far enough.

Looking just at the forwarding plane. We welcome the support of BGP standard 
and extended communities. To be useable for us, we would also need BGP 
route-distinguishers (IPFIX entity 90) and prefix/prefix length to be covered 
to be applicable in a MPLS VPN network. I agree with Jeffrey that the 
correlation from BGP local RIB to the RIB on the router is more accurate (lag, 
BGP local RIB vs. RIB), compared to the correlation between BGP local rib and 
IPFIX on a collector.

Looking at the big picture, IPFIX is just covering the forwarding plane. It is 
just a part of the puzzle to extract metrics from a router. The forwarding 
plane alone isn't enough to understand why the forwarding behavior changed in a 
network. BMP is covering well the routing control-plane, especially if BGP 
local RIB and adjacent RIB out will be covered. Streaming telemetry with yang 
config model covering the physical topology. From our point of view, where we 
want forwarding, control-plane and physical topology covered, I disagree that 
the BGP/BMP peering could be replaced by this draft. It will remain to cover 
the historical aspects of the BGP control-plane. It could be replaced if we 
only would care about the forwarding plane (for accounting as an example) 
though.

Kind regards
Thomas Graf

Network Engineer
Tribe IT Clouds
Telefon +41-58-223 84 01
Mobile   +41-79-728 80 12
thomas.g...@swisscom.com<mailto:thomas.g...@swisscom.com>

Swisscom (Schweiz) AG
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From: GROW [mailto:grow-boun...@ietf.org] On Behalf Of li zhenqiang
Sent: Tuesday, February 27, 2018 5:06 PM
To: Jeffrey Haas ; Paolo Lucente 
Cc: grow ; Zhoutianran ; 
draft-ietf-opsawg-ipfix-bgp-community@ietf.org; opsawg 
Subject: Re: [GROW] WG LC for draft-ietf-opsawg-ipfix-bgp-community

Hi Jeffrey Haas and Paolo Lucente,

Thank you very much for your comments and opinions. Sorry for the late response 
due to Chinese new year holiday.

For the first concern of Paolo, at present I have no need to know the full as 
path related to a traffic flow. What I want to collect is the communities 
related to a traffic flow, which represent the the geographical and topological 
related information in finer granularity than the ASes.


When the working group called adoption of this doc, IPFIX doctor, PJ Aitken's 
opinion answered your second concern.  He said " Per section 6 of RFC7012, new 
IPFIX Information Elements can be added by direct application to IANA; there's 
no need for a draft or RFC. However, the introduction and examples may be 
valuable, especially for BGP experts who are less familiar with IPFIX. I've no 
objection to adopting the draft."


And I totally agree with Mr. Jeffrey Haas, running BGP is not trivial for all 
the IPFIX collectors. BGP is heavy and it runs well in the exporters, i.e. 
routers. If the collector can get the needed BGP information, it can do 
statistics and analysis directly.


Best Regards,
Zhenqiang Li from China Mobile Research Institute

li_zhenqi...@hotmail.com<mailto:li_zhenqi...@hotmail.com>

From: Jeffrey Haas<mailto:jh...@pfrc.org>
Date: 2018-02-22 01:52
To: Paolo Lucente<mailto:pa...@ntt.net>
CC: Tianran Zhou<mailto:zhoutian...@huawei.com>; 
grow@ietf.org<mailto:grow@ietf.org>; 
draft-ietf-opsawg-ipfix-bgp-community@ietf.org<mailto:draft-ietf-opsawg-ipfix-bgp-community@ietf.org>;
 opsawg<mailto:ops...@ietf.org>
Subject: Re: [GROW] WG LC for draft-ietf-opsawg-ipfix-bgp-community
Paolo,

I don't speak for the authors here, just my opinion.

On Wed, Feb 21, 2018 at 05:37:59PM +0100, Paolo Lucente wrote:
> 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.

Partly, the usual information that people want from flow for AS information
(origin or peer AS) is already available.  The full path, no.  One certainly
could make the argument that the full path could be sent.

Since flow analyzers mos

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

2018-02-27 Thread li zhenqiang
Hi Jeffrey Haas and Paolo Lucente,

Thank you very much for your comments and opinions. Sorry for the late response 
due to Chinese new year holiday.

For the first concern of Paolo, at present I have no need to know the full as 
path related to a traffic flow. What I want to collect is the communities 
related to a traffic flow, which represent the the geographical and topological 
related information in finer granularity than the ASes.

When the working group called adoption of this doc, IPFIX doctor, PJ Aitken's 
opinion answered your second concern.  He said " Per section 6 of RFC7012, new 
IPFIX Information Elements can be added by direct application to IANA; there's 
no need for a draft or RFC. However, the introduction and examples may be 
valuable, especially for BGP experts who are less familiar with IPFIX. I've no 
objection to adopting the draft."

And I totally agree with Mr. Jeffrey Haas, running BGP is not trivial for all 
the IPFIX collectors. BGP is heavy and it runs well in the exporters, i.e. 
routers. If the collector can get the needed BGP information, it can do 
statistics and analysis directly.

Best Regards,
Zhenqiang Li from China Mobile Research Institute

li_zhenqi...@hotmail.com

From: Jeffrey Haas<mailto:jh...@pfrc.org>
Date: 2018-02-22 01:52
To: Paolo Lucente<mailto:pa...@ntt.net>
CC: Tianran Zhou<mailto:zhoutian...@huawei.com>; 
grow@ietf.org<mailto:grow@ietf.org>; 
draft-ietf-opsawg-ipfix-bgp-community@ietf.org<mailto:draft-ietf-opsawg-ipfix-bgp-community@ietf.org>;
 opsawg<mailto:ops...@ietf.org>
Subject: Re: [GROW] WG LC for draft-ietf-opsawg-ipfix-bgp-community
Paolo,

I don't speak for the authors here, just my opinion.

On Wed, Feb 21, 2018 at 05:37:59PM +0100, Paolo Lucente wrote:
> 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.

Partly, the usual information that people want from flow for AS information
(origin or peer AS) is already available.  The full path, no.  One certainly
could make the argument that the full path could be sent.

Since flow analyzers mostly want the active route's properties, having the
communities to go along with it is helpful.

> 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.

Analyzers still find it handy to have source and destination AS.  This in
some cases avoids lag issues due to propagation of sniffed BGP (via iBGP
peering or BMP) for the sampling router.  Additionally, a lot of useful data
can be gathered without having BGP at all at the analyzer.

I do understand the concern, but personally find it unlikely that this is
the feared "slippery slope". [1]

-- Jeff

[1] https://en.wikipedia.org/wiki/Slippery_slope
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Re: [GROW] WG LC for draft-ietf-opsawg-ipfix-bgp-community

2018-02-21 Thread Jeffrey Haas
Paolo,

I don't speak for the authors here, just my opinion.

On Wed, Feb 21, 2018 at 05:37:59PM +0100, Paolo Lucente wrote:
> 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.

Partly, the usual information that people want from flow for AS information
(origin or peer AS) is already available.  The full path, no.  One certainly
could make the argument that the full path could be sent.

Since flow analyzers mostly want the active route's properties, having the
communities to go along with it is helpful.

> 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. 

Analyzers still find it handy to have source and destination AS.  This in
some cases avoids lag issues due to propagation of sniffed BGP (via iBGP
peering or BMP) for the sampling router.  Additionally, a lot of useful data
can be gathered without having BGP at all at the analyzer.

I do understand the concern, but personally find it unlikely that this is
the feared "slippery slope". [1]

-- Jeff

[1] https://en.wikipedia.org/wiki/Slippery_slope

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

2018-02-21 Thread Paolo Lucente

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  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 ops...@ietf.org?
> 
> Cheers,
> Tianran, as OPSAWG co-chair
> 
> 
> -Original Message-
> From: OPSAWG [mailto:opsawg-boun...@ietf.org] On Behalf Of Tianran Zhou
> Sent: Thursday, January 18, 2018 11:07 AM
> To: ops...@ietf.org
> Cc: opsawg-cha...@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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> https://www.ietf.org/mailman/listinfo/opsawg
> 
> ___
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