Re: [Lsr] [Idr] [GROW] IGP Monitoring Protocol

["Acee Lindem (acee)" <[e-mail]>]

Hi Robert,

From: Lsr <[e-mail]> on behalf of Robert Raszuk <[e-mail]>
Date: Sunday, July 10, 2022 at 1:32 PM
To: Yingzhen Qu <[e-mail]>
Cc: Gyan Mishra <[e-mail]>, Susan Hares <[e-mail]>, IDR List <[e-mail]>, "[e-mail] [e-mail]" <[e-mail]>, lsr <[e-mail]>
Subject: Re: [Lsr] [Idr] [GROW] IGP Monitoring Protocol

Hi Yingzhen & OSPF-GT authors,

UP front I must state that anything is better to export IGP information from routers to interested nodes than using BGP for it.

But to propose using OSPF to transport ISIS seems pretty brave :) I must admit it !

With that I have few questions to the proposal - assuming the use case is to distribute links state info in a point to point fashion:


  1.  What is the advantage - if any - to use a new OSPF instance/process to send link state data over a unicast session to a controller ?

It doesn’t have to be unicast, the remote neighbor construct just extends the possibilities in OSPF-GT. With an OSPF LSDB, the obvious advantage is all the protocol machinery is in place.  Note that LSDB streaming is just but one use case and of OSPF-GT. The detals of this application would be specified in a separate draft.



  1.  The draft is pretty silent on the nature of such a p2p session. Please be explicit if this is TCP, QUIC or what ?

It is OSPF, OSPF has its own protocol identifier (89). This draft just extends OSPF. I think you’ve misinterpreted the draft. Hence, your other questions aren’t really applicable or would be answered in a draft of the OSPF/IS-IS LSDB usage of OSPF-GT.

Thanks,
Acee



C) The draft is pretty silent on types of authentication for such sessions. Security considerations are pretty weak in that respect as well.

   The security considerations for OSPF-GT will be similar to those for
   OSPFv2 [RFC2328] and OSPFv3 [RFC5340].  However, since OSPF-GT is not
   used to update OSPF routing, the consequences of attacks will be
   dependent on advertised non-routing information.

I would actually argue that security considerations of p2p remote neighbors are actually quite different from security considerations of flooding data.

Along the same lines security is not about protecting your routing ... it is much more about protecting the entire network by exposing critical information externally to non authorized parties.

D) Are there any PUB-SUB options possible for OSPF-GT ?

E) Is there any filtering possible for OSPF-GT ?

F) Are you envisioning use of OSPF-GT proxies and if so are you planning to add this to the document ?

G) How are you going to address Receivers which do not support OSPF-GT parser ?

H) As you know many operators are attracted to BGP-LS based on the fact that it offers the same view of information irrespective of what is the protocol producing the data. Is there some thought on such normalization in the OSPF-GT proposal ?

I) What's the take of OSPF-GT draft authors on the YANG model in respect of using it for normalization of exported data ?

To summarize IMHO we should not stretch routing protocols be it OSPF, ISIS or BGP to be messengers of link state data running and to artificially force them to run in a point-to-point model between router and controller.

Kind regards,
Robert


On Sun, Jul 10, 2022 at 7:04 AM Yingzhen Qu <[e-mail]<mailto:[e-mail]>> wrote:
Hi,

Since we’re discussing possible solutions, I’d like to bring up the draft: https://datatracker.ietf.org/doc/draft-ietf-lsr-ospf-transport-instance/

We just submitted a new version. The name of the document is changed to “OSPF-GT (Generalized Transport)”, and a use case is added to use OSPF-GT as a possible replacement of BGP-LS.

Note: OSPF-GT is not traditional OSPF, and it’s not used to calculate routes. It uses the reachability info calculated by routing protocols, OSPF, ISIS or static routing etc.. It provides mechanisms to advertise non-routing information, and remote neighbor is supported.

Reviews and comments are welcome.


Thanks,
Yingzhen


On Jul 9, 2022, at 5:33 PM, Gyan Mishra <[e-mail]<mailto:[e-mail]>> wrote:


During the interim meeting we should keep it open to discuss all possible alternatives to BGP-LS.

Thanks

Gyan

On Sat, Jul 9, 2022 at 4:45 PM Susan Hares <[e-mail]<mailto:[e-mail]>> wrote:
Jeff:

An interim sounds like a good plan.

[IDR-chair hat]
Alvaro has indicated that since all of the proposal received on the IDR list are new protocol proposals,
·         Capturing IDR’s input on BGP-LS problems and potential solutions is appropriate for IDR as BGP-LS home.
·         Refining any potential non-BGP solutions is outside of the scope of IDR.

[IDR-chair hat off]
[rtgwg WG member]
I’d love to attend an interim on this topic.

Sue Hares


From: Jeff Tantsura <[e-mail]<mailto:[e-mail]>>
Sent: Saturday, July 9, 2022 3:40 PM
To: Robert Raszuk <[e-mail]<mailto:[e-mail]>>
Cc: Acee Lindem (acee) <[e-mail]<mailto:[e-mail]>>; lsr <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; Susan Hares <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]> [e-mail]<mailto:[e-mail]> <[e-mail]<mailto:[e-mail]>>
Subject: Re: [Idr] [Lsr] IGP Monitoring Protocol



Speaking as RTGWG chair:

Robert - I don’t think we’d have enough time to accommodate a good discussion during IETF114 (we got only 1 slot), however would be happy to provide a platform for an interim.
The topic is important and personally (being a very large BGP-LS user) I’d like to see it progressing.
Cheers,
Jeff

On Jul 8, 2022, at 14:44, Robert Raszuk <[e-mail]<mailto:[e-mail]>> wrote:
Hi Acee,

Yes, by all means input from the operator's community is needed. It can be collected through LSR WG, IDR WG or GROW WG. RTGWG could also contribute. We have already seen input from some operators and their opinion on adding and distributing more and more link state protocol and topology data in BGP. More such input is very welcome.

And to your point about RFC9086 - I see nothing wrong in keeping BGP information in BGP. So IGP Monitoring Protocol does not target to shut down BGP-LS. It only aims to remove 100% of non BGP sourced information from it.

Controllers which today listen to BGP-LS need a number of information sources and that spread will only keep increasing as more inputs are becoming necessary for its computations.

Regards,
Robert.


On Fri, Jul 8, 2022 at 11:32 PM Acee Lindem (acee) <[e-mail]<mailto:[e-mail]>> wrote:
Hi Robert,

From: Robert Raszuk <[e-mail]<mailto:[e-mail]>>
Date: Friday, July 8, 2022 at 4:36 PM
To: Acee Lindem <[e-mail]<mailto:[e-mail]>>
Cc: lsr <[e-mail]<mailto:[e-mail]>>, IDR List <[e-mail]<mailto:[e-mail]>>, Susan Hares <[e-mail]<mailto:[e-mail]>>
Subject: Re: [Lsr] IGP Monitoring Protocol

Hi Acee,

Thank you. I was not planning to present it in the upcoming IETF.

> Let’s see how many stakeholders actually want to this protocol - then we can talk about a WG home.

An alternative approach could be to see how many stakeholders do not want to further (for no good reason) to trash BGP. That to me would be in this specific case a much better gauge.

In that case, it seems to me that this discussion should be relegated to IDR. Note that there is already non-IGP information transported in BGP-LS, e.g., Egress Peer Engineering (https://datatracker.ietf.org/doc/rfc9086/). I implemented this on our data center routers (NXOS) years and it is solely BGP specific.

Thanks,
Acee

Kind regards,
Robert


On Fri, Jul 8, 2022 at 9:54 PM Acee Lindem (acee) <[e-mail]<mailto:[e-mail]>> wrote:
Speaking as WG chair:

From: Lsr <[e-mail]<mailto:[e-mail]>> on behalf of Robert Raszuk <[e-mail]<mailto:[e-mail]>>
Date: Friday, July 8, 2022 at 3:21 PM
To: lsr <[e-mail]<mailto:[e-mail]>>
Cc: IDR List <[e-mail]<mailto:[e-mail]>>, Susan Hares <[e-mail]<mailto:[e-mail]>>
Subject: [Lsr] IGP Monitoring Protocol

Dear LSR WG,

Based on ongoing discussion in respect to the future of BGP-LS I committed myself to put together an alternate proposal.

The main goal is not to just publish a -00 version of the draft using different encapsulation. The goal is to make a useful tool which can help to export link state information from network elements as well as assist in network observability.

The IGP Monitoring Protocol (IMP) draft has been posted and should be available at:

https://datatracker.ietf.org/doc/draft-raszuk-lsr-imp/

One of the key points I wanted to accomplish was full backwards compatibility with TLVs defined for BGP-LS. In parallel other formats (optional) are also supported.

The PUB-SUB nature or FILTERING capabilities are in the spec however as noted in the deployment section there is no expectation that this should be supported directly on routers. Concept of Producer's Proxies has been introduced to support this added functionality as well as provide fan-out (analogy to BGP route reflectors).

I encourage everyone interested to take a look and provide comments. At this point this document is nothing more than my individual submission. Offline I have had few conversations with both operators and vendors expressing some level of interest in this work. How we proceed further (if at all :) depends on WG feedback.

Kind regards,
Robert.

PS, I do believe this work belongs in LSR WG pretty squerly.

Let’s see how many stakeholders actually want to this protocol - then we can talk about a WG home.  By stakeholders, I mean operators and vendors who are committed to implementing and deploying it - not simply those who you are able to enlist as co-authors. Note that our IETF 114 LSR agenda is full (with multiple agenda items not making the cut).

Thanks,
Acee



_______________________________________________
Idr mailing list
[e-mail]<mailto:[e-mail]>
https://www.ietf.org/mailman/listinfo/idr
_______________________________________________
GROW mailing list
[e-mail]<mailto:[e-mail]>
https://www.ietf.org/mailman/listinfo/grow
--

[Image removed by sender.]<http://www.verizon.com/>
Gyan Mishra
Network Solutions Architect
Email [e-mail]<mailto:[e-mail]>
M 301 502-1347

_______________________________________________
Idr mailing list
[e-mail]<mailto:[e-mail]>
https://www.ietf.org/mailman/listinfo/idr