Aijun, > And, if the interfaces share the same prefixes, they are in the same IP subnet.
That is unfortunately a wrong assumption. In number of deployments all external links can share the same IP addresses as they are terminated in VRFs and on the other side belong to completely different peers. So unless you add an RD to those prefixes and make them domain wide unique I am afraid your proposal has serious issue. As Les said when we define a protocol extension the most important is to review how it will work in all deployment cases - not to pick just a few and declare a success. Regards, Robert On Wed, Jan 17, 2024 at 7:56 AM Aijun Wang <[email protected]> wrote: > Hi, Les: > > Let’s keep the discussions simple. > > Please answer the following two questions that you haven’t responsed > directly in previous mail: > 1) How the existing point-to-point based solution(RFC9346/RFC5392) solve > the broadcast(LAN, A.1 Figure2) inter-AS topology recovery scenario---There > are multiple neighbors on one interfaces, which are located in different > AS. How to encode the information within one inter-AS reachability TLV? > 2) How the inter-AS based solutions solve the non inter-AS scenario > requirements(A.2)? > > One point that I want to remind for your misunderstanding: the proposed > Stub-link TLV can contain other attributes sub-TLVs of the link. > And, if the interfaces share the same prefixes, they are in the same IP > subnet. Is there any ambiguously for the IP topology recovery? > > What I want to emphasize is that the existing solutions are suitable for > inter-AS point-to-point TE, the proposed solutions are suitable(more > efficient)for inter-AS topology recovery(p2p, p2mp and broadcast etc.) and > also other non inter-as traffic optimization scenarios. They are not > contrary. > > > > Aijun Wang > China Telecom > > On Jan 17, 2024, at 00:57, Les Ginsberg (ginsberg) <ginsberg= > [email protected]> wrote: > > > > Aijun – > > > > Please see inline. > > > > *From:* Aijun Wang <[email protected]> > *Sent:* Tuesday, January 16, 2024 12:18 AM > *To:* Les Ginsberg (ginsberg) <[email protected]>; 'Christian Hopps' < > [email protected]>; 'Huzhibo' <[email protected]> > *Cc:* 'Acee Lindem' <[email protected]>; 'Yingzhen Qu' < > [email protected]>; [email protected] > *Subject:* 答复: [Lsr] WG Adoption Call - > draft-wang-lsr-stub-link-attributes (01/05/2024 - 01/19/2024) > > > > Hi, Les: > > > > -----邮件原件----- > 发件人: [email protected] [mailto:[email protected] > <[email protected]>] 代表 Les Ginsberg (ginsberg) > 发送时间: 2024年1月16日 0:16 > 收件人: Christian Hopps <[email protected]>; Huzhibo < > [email protected]> > 抄送: Acee Lindem <[email protected]>; Yingzhen Qu < > [email protected]>; [email protected] > 主题: Re: [Lsr] WG Adoption Call - draft-wang-lsr-stub-link-attributes > (01/05/2024 - 01/19/2024) > > > > I respect that individuals may have different opinions - but it is > important to distinguish what is factual from what is not. > > Opinions based upon false information are clearly compromised. > > > > Please do heed Chris's (as WG chair) admonition to review the first WG > adoption thread. That will reveal to you what the substantive objections > were. > > > > https://mailarchive.ietf.org/arch/msg/lsr/Li7wJsaY68gzJ8mXxff7K-Fy_nw/ > > https://www.mail-archive.com/search?l=lsr%40ietf.org&q=stub+link&x=0&y=0 > > > > > > Please also do examine the delta between the previous version which was > put up for WG adoption (V3) and the current version (V8) so you can see > what has changed. > > > https://author-tools.ietf.org/iddiff?url1=draft-wang-lsr-stub-link-attributes-03&url2=draft-wang-lsr-stub-link-attributes-08&difftype=--html > > > > Some facts: > > > > The substantive objections raised during the first adoption call had > nothing to do with use cases - they had to do with: > > > > a)The use of a prefix to identify a link between two nodes is a flawed > concept. It is not robust enough to be used in cases of unnumbered or > Pt-2-MP. > > [WAJ] Current encoding has covered the unnumbered scenario. For Pt-2-MP > scenario, they share also the same subnet, please see our previous > discussion at > https://mailarchive.ietf.org/arch/msg/lsr/molRRoWXOBhaHFc5GPAPmvVISDs/ > > > > *[LES:] I have no idea why you think the email you point to resolved the > issue. It was an early email in a very long thread, the lack of support for > unnumbered etc. continued to be discussed in subsequent emails by multiple > participants and has been raised again by multiple participants in this > second adoption call thread.* > > *The minor changes you made to the encoding of Stub Link advertisement > does nothing to resolve the issue.* > > *The fundamental issue is that the same prefix can be associated with > multiple links, so what you have defined is ambiguous in some cases.* > > *Either you don’t understand this or don’t think this is important – I am > not sure which – but many of us do believe this is important.* > > > > b)Existing mechanisms (RFC 9346/was RFC 5316 and RFC 5392) fully cover the > potential use cases and do so more robustly than the Stub-link proposal. > > [WAJ] If you make such claims, then please give the encoding example for > A.1 Figures 2(LAN scenario). How to configure/encode the several neighbors > that located in different AS in one inter-AS reachability TLV? > > > > *[LES:] RFC 9346/RFC 5362 provide a robust way to uniquely identify > inter-AS links, verify two-way connectivity, and optionally advertise > additional link attributes if desired. (Apply this portion of the response > to your other comments below.)* > > *You apparently think this is too onerous and you propose a different > mechanism that isn’t robust, does not allow two-way connectivity > verification, and doesn’t support link attribute advertisement.* > > *But because you see it as “simpler” you think you have sufficient > justification to overlook its flaws.* > > *I don’t agree.* > > > > *The long-lived success of the IGPs has happened because we have worked > diligently to provide robust solutions – not settle for solutions that only > work some of the time.* > > > > * Les* > > > > The latest version of the draft makes no substantive changes to the stub > link concept or its advertisement. > > The only substantive change in the latest version is a reorganization of > the presentation of use cases. > > But lack of clarity in the use cases was not the basis on which first WG > adoption call was rejected. > > > > In this thread (the second WG adoption call), the authors have asserted > that they have addressed the concerns raised in the previous adoption call. > > They have not. The concept and mechanism to identify a stub link has not > changed. > > > > In this thread the authors continue to assert that RFC 9346/RFC 5392 > cannot address the use cases. > > This is FALSE. > > As has been pointed out repeatedly, the existing mechanisms provide a > robust means to uniquely identify inter-AS links using endpoint identifiers > - be they IPv4/IPv6 addresses or Link IDs. > > [WAJ] And, please give the solution for the non inter-AS scenario(A.2). > Please do not mention the bogus AS again > > > > This addresses all cases - numbered and unnumbered. > > There is therefore no need for a new mechanism. > > [WAJ] Repeat again. The requirements of inter-AS TE solution are different > from the requirements of inter-AS topology recovery. We should find more > efficient solution to solve the latter scenario. > > The inefficiency of existing solutions for inter-AS topology recovery lies > in that it requires the operators to get the other end information for > every inter-as links manually, this is very challenge and error-prone, as > that also indicated in RFC9346 and RFC5392 themselves. > > > > No fact-based argument has been made to justify reconsideration of WG > adoption. > > > > I hope when people post their opinions, that they consider the facts. > > > > Les > > > > > -----Original Message----- > > > From: Lsr <[email protected]> On Behalf Of Christian Hopps > > > Sent: Wednesday, January 10, 2024 2:17 AM > > > To: Huzhibo <[email protected]> > > > Cc: Acee Lindem <[email protected]>; Yingzhen Qu > > > <[email protected]>; [email protected] > > > Subject: Re: [Lsr] WG Adoption Call - > > > draft-wang-lsr-stub-link-attributes > > > (01/05/2024 - 01/19/2024) > > > > > > [As WG Co-Chair] > > > > > > Hi Folks, > > > > > > Before posting support reasons please read and considerl > > > *all* the email in the archive covering the first failed > > > adoption call. > > > > > > https://mailarchive.ietf.org/arch/msg/lsr/Li7wJsaY68gzJ8mXxff7K-Fy_nw/ > > > https://www.mail- > > > archive.com/search?l=lsr%40ietf.org&q=stub+link&x=0&y=0 > > > > > > This adoption call should be considering if the changes > > > made to the document since it failed to be adopted the > > > first time, are sufficient to reverse the WGs previous > > > decision. > > > > > _______________________________________________ > > Lsr mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/lsr > _______________________________________________ > Lsr mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/lsr > > _______________________________________________ > Lsr mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/lsr >
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