pretty obvious +1 here --- tony
On Tue, Jul 24, 2018 at 3:41 AM Rob Shakir <[email protected]> wrote: > +1 to Peter. We should not define fragile solutions within the IETF. > > There are also a multitude of other solutions here already: > > 1) IGP adjacency with one router in each area (at a minimum - probably two > for a robust system) over a tunnel. Deployed in many networks for years. > 2) BGP-LS to one router (ditto robustness comment) in each area. > 3) streaming telemetry of the LSDB contents via gNMI. > > All these solutions exist in shipping implementations - please let’s not > add to the system complexity of the IGP here. > > r. > On Mon, Jul 23, 2018 at 12:30 Peter Psenak <ppsenak= > [email protected]> wrote: > >> Hi Aijun, >> >> On 23/07/18 13:07 , Aijun Wang wrote: >> > Hi, Peter: >> > >> > For routers that connected by LAN, the router will establish adjacent >> > neighbor with DR, but not only DR advertises the connected prefixes. >> >> only the Network LSA includes the network mask, other routers would >> include the interface address only. >> >> >> > DR and >> > DRother will all advertise type 1 and type 2 LSA with each other, then >> the >> > process and proposal described in this draft will still work. >> > We seldom use the ip unnumbered features in our network, can we ignore >> it >> > then? Or other persons has some idea on such situation? >> >> the fact that you do not use unnumbered is not really relevant. IETF >> defines solutions that MUST work for all possible scenarios, not only >> for a specific one. >> >> > Anycast prefixes are often /32 long, this can be easily filtered by SDN >> > controller because the link prefixes between two routers will be no >> larger >> > than /32 for IPv4 network. >> >> protocol allows to advertise the same prefix with an arbitrary mask from >> multiple routers without these routers being directly connected. Your >> proposal is based on the assumptions that are incorrect. >> >> thanks, >> Peter >> >> > >> > Best Regards. >> > >> > Aijun Wang >> > Network R&D and Operation Support Department >> > China Telecom Corporation Limited Beijing Research Institute,Beijing, >> China. >> > >> > -----邮件原件----- >> > 发件人: Peter Psenak [mailto:[email protected]] >> > 发送时间: 2018年7月23日 18:20 >> > 收件人: Aijun Wang; 'Peter Psenak'; [email protected] >> > 抄送: [email protected]; 'Ketan Talaulikar (ketant)'; 'Acee Lindem (acee)'; >> > 'Dongjie (Jimmy)' >> > 主题: Re: [Lsr] 答复: Regarding OSPF extension for inter-area topology >> > retrieval >> > >> > Hi Aijun, >> > >> > On 23/07/18 11:16 , Aijun Wang wrote: >> >> Hi, Peter: >> >> >> >> Actually, I consider mainly the point-to-point connection and the >> >> numbered interface, which are normal in our network. >> >> For the two situations that you mentioned, I will investigation the >> >> possible solutions and feedback you later. >> >> >> >> For the point-to-point and numbered interface, do you have other >> >> questions then? >> > >> > the fact that two routers announce the same subnet, does not mean they >> are >> > connected together by p2p link. Anycast prefix is an example. >> > >> > The idea you are proposing simply does not work. >> > >> > thanks, >> > Peter >> > >> > >> >> >> >> Best Regards. >> >> >> >> Aijun Wang >> >> Network R&D and Operation Support Department China Telecom Corporation >> >> Limited Beijing Research Institute,Beijing, China. >> >> >> >> -----邮件原件----- >> >> 发件人: Peter Psenak [mailto:[email protected]] >> >> 发送时间: 2018年7月23日 16:15 >> >> 收件人: Aijun Wang; [email protected] >> >> 抄送: [email protected]; 'Ketan Talaulikar (ketant)'; 'Acee Lindem (acee)'; >> >> 'Dongjie (Jimmy)' >> >> 主题: Re: [Lsr] Regarding OSPF extension for inter-area topology >> >> retrieval >> >> >> >> Hi Aijun, >> >> >> >> you are trying to reconstruct the topology of the remote area based on >> >> the fact that two routers are connected to the same subnet. It does >> >> not work >> >> because: >> >> >> >> 1. connections between routers can be unnumbered 2. routers can be >> >> connected via LAN, in which case only DR announces the prefix. >> >> >> >> In summary, what you propose does not work. >> >> >> >> thanks, >> >> Peter >> >> >> >> >> >> >> >> On 23/07/18 09:49 , Aijun Wang wrote: >> >>> (Sorry for my previous mail sent wrongly to the IDR mail list, please >> >>> reply on this thread within the LSR wg) >> >>> >> >>> Hi, Peter: >> >>> >> >>> I am Aijun Wang from China Telecom, the author of draft about “OSPF >> >>> extension for inter-area topology retrieval” >> >>> <https://datatracker.ietf.org/doc/draft-wang-lsr-ospf-inter-area-topo >> >>> l ogy-ext/>, which is presented by Mr.Jie Dong during the IETF102 >> >>> meeting. >> >>> >> >>> Thanks for your comments on the presentation material >> >>> >> >> <https://datatracker.ietf.org/meeting/102/materials/slides-102-lsr-osp >> >> f-inte >> >> r-area-topology-retrieval-00>. >> >>> >> >>> Below are my explanation that regarding to the question about “how it >> >>> retrievals the inter-area topology based on the extension >> information”: >> >>> >> >>> Let’s see the graph that illustrates in Fig.1 at section 3 >> >>> <https://tools.ietf.org/html/draft-wang-lsr-ospf-inter-area-topology- >> >>> e xt-00#section-3> of the draft(I copy it also below for your >> >>> conveniences ): >> >>> >> >>> Assuming we want to rebuild the connection between router S1 and >> >>> router >> >>> S2 that locates in area 1: >> >>> >> >>> 1)Normally, router S1 will advertise prefix N1 within its router LSA >> >>> >> >>> 2)When this router LSA reaches the ABR router R1, it will convert it >> >>> into summary LSA, add the “Source Router Information”, which is >> >>> router id of S1 in this example, as proposed in this draft. >> >>> >> >>> 3)R1 then floods this extension summary LSA to R0, which is running >> >>> BGP-LS protocol with IP SDN Controller. The controller then knows the >> >>> prefixes of N1 is from S1. >> >>> >> >>> 4)Router S2 will do the similar process, and the controller will also >> >>> knows the prefixes N1 is also from S2 >> >>> >> >>> 5)Then it can reconstruct the connection between S1 and S2, which >> >>> prefix is N1. The topology within Area 1 can then be recovered >> >> accordingly. >> >>> >> >>> Does the above explanation can answer your question. if so, I can add >> >>> it into the context of this draft in updated version. >> >>> >> >>> Best Regards. >> >>> >> >>> Aijun Wang >> >>> >> >>> Network R&D and Operation Support Department >> >>> >> >>> China Telecom Corporation Limited Beijing Research Institute,Beijing, >> >> China. >> >>> >> >> >> >> _______________________________________________ >> >> 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 >> > >> > . >> > >> >> _______________________________________________ >> 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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