Dear Rayhaan, Thank you for working on this draft.
As far as your suggestion to use new SAFI to auto discover presence and addresses of Looking Glass servers across ASN boundaries I have nothing against. As you know the alternative to exchange this type of information would be via defining a new BGP Message (just like we ddi this in the past in case of BGP Operational Message). But here perhaps you want to propagate this beyond single ASN peer so new SAFI may work better. I however have one major concern on how are Looking Glasses going to help to address your original problem ie. to check if my prefix was announced and accepted by peering AS. Note that ASBRs normally send only best paths. If best path was learned over IBGP (tie breaker was Local Pref or MED) ASBR may receive and accept your route, but that route would not be advertised to LGs. The natural solution here is use of best external and add-paths to make sure LGs really get all received and accepted paths for a given net - but I am not sure how common that is deployed today on sessions between ASBRs and LGs. Last time I checked LGs get peering with RRs and get RR paths. Even with add-path there and no best external your original issue would not be solved. So I would recommend that we review this point before focusing more on LG auto discovery mechanics. Btw this draft if progressing should be IMO discussed in IDR and changed to Standards Track. But GROW is an excellent forum to first make sure if the entire idea proposed here is sound enough. Best, R. On Sun, Jul 25, 2021 at 9:24 PM Rayhaan Jaufeerally (IETF) <i...@rayhaan.ch> wrote: > Dear GROW WG, > > Following the feedback previously on my looking glass draft proposal, I've > updated the looking glass draft ( > https://datatracker.ietf.org/doc/draft-jaufeerally-bgp-lg-cap/), to move > away from a capability mechanism to a new AFI which uses the MP_REACH and > MP_UNREACH messages in the BGP multiprotocol specification ( > https://datatracker.ietf.org/doc/html/rfc4760) to carry an administrative > message. This administrative message is then defined to have a payload type > that carries a URL for the looking glass (LG), as well as the ASN that is > operating the LG. > > The advantage of this approach is that it allows for propagating the LGs > of upstream peers so leaf ASes can check prefix reachability in peers not > directly connected. > > Looking at the development of the idea, I think it could make sense to > split the document into one for the administrative message and AFI, and > another for the looking glass message type within that. > > I will present an overview of the draft and the expected use cases during > the upcoming GROW meeting at IETF111, so feel free to either comment here > or ask a question in the session if you have any feedback. > > Thanks, > Rayhaan > > > > On Tue, Apr 27, 2021 at 1:29 PM Job Snijders <j...@fastly.com> wrote: > >> On Mon, Apr 26, 2021 at 01:16:55AM +0200, Rayhaan Jaufeerally (IETF) >> wrote: >> > > Consistent API that serves RIB data >> > >> > Initially I tried to avoid defining the exact API of the looking glass >> by >> > pointing to https://tools.ietf.org/html/rfc8522, but unfortunately it >> does >> > not strictly define the response format instead leaving it up to the >> > implementation what to return to queries, which IMO is not very useful >> for >> > automation. >> > >> > As y'all have pointed out there is a wealth of implementations out there >> > that have tried to address this (and adding some others I've found): >> > >> > - Paolo's pmacct looking glass document: >> > >> https://github.com/pmacct/pmacct/blob/master/docs/LOOKING_GLASS_FORMAT, >> > - Birdseye https://github.com/inex/birdseye >> > - CAIDA looking glass API >> > https://www.caida.org/tools/utilities/looking-glass-api/ >> > - DE-CIX: https://www.de-cix.net/en/resources/looking-glass (which >> is >> > using https://github.com/alice-lg/alice-lg) >> > - RIPEStat's API, e.g. >> > >> https://stat.ripe.net/data/looking-glass/data.json?preferred_version=2.1&resource=2a0d:d740::/48 >> >> Just to add to the list: there is yet another API-based Looking Glass >> targetting OpenBGPD: https://github.com/cjeker/bgplgd >> >> A demo is here: >> http://165.22.27.105/bgplgd/summary >> http://165.22.27.105/bgplgd/rib?as=22512 >> >> Kind regards, >> >> Job >> > _______________________________________________ > GROW mailing list > GROW@ietf.org > https://www.ietf.org/mailman/listinfo/grow >
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