Hi Yakov, I read Eric's email and included its main point a bit differently.
It is known for a fact that in large network (say 1000 routers) it is sufficient to force traffic only via few key core boxes (perhaps 10 or so) in order to perform good traffic engineering. With SR it is possible while in classical RSVP-TE it is not - simply due hop by hop signalling nature of the latter. His reference to PE was IMHO just an example without intention to provide exhaustive list. For local protection with basic IPv6 network I would rather recommend use of LFA solutions which again do not require anything to do with SRH processing - so his SRH forwarding only case for vast majority of routers in a given domain remains sound and valid. Best regards, R. On Fri, May 30, 2014 at 9:37 PM, Yakov Rekhter <[email protected]> wrote: > Eric, > >> -----Original Message----- >> From: Eric Vyncke (evyncke) [mailto:[email protected]] >> Sent: Tuesday, May 27, 2014 2:37 PM >> To: Hannes Gredler; Stefano Previdi (sprevidi) >> Cc: Yakov Rekhter; <[email protected]>; Alvaro Retana (aretana) >> Subject: Re: [spring] WG Adoption Call for draft-martin-spring-segment- >> routing-ipv6-use-cases >> >> Late reply to Hannes point: >> >> On 28/03/14 22:23, "Hannes Gredler" <[email protected]> wrote: >> > >> >the real question is what percentage of public Internet routers >> > >> >1) does have MPLS hardware forwarding support >> >2) does have IPv6-SR hardware forwarding support. >> > >> >And >> >> Regarding the IPv6-SR compatibility, as SRH is basically 'loose source >> routing', it only requires: >> - SRH processing by all SR-enabled router whose segment id is in the >> SRH, typically some PE routers. Those will need to be modified indeed >> but those will be minority >> - SRH forwarding (i.e. Not parsing or acting upon the SRH) for all >> remaining routers. Those will be the majority > > If indeed, as you said above, only "minory" of the routers (e.g., only PEs) > would be able to process IPv6 SRH, then SR would *not* be able to support > such use cases as various flavors of local protection, and traffic engineering > (except for EPE). Conversely, support for various flavors of local > protection and/or traffic engineering (other than EPE) would require > all routers to support IPv6 SRH. > > Yakov. > >> >> The latter is currently OK, I wrote a small script >> https://www.vyncke.org/sr.php which basically sends a dummy SRH to your >> browser (requirement is that your browser/clients supports IPv6) and >> after a dozen of tests, all were successful. While this is not a >> mathematical proof, this is good enough from my engineer's point of >> view >> >> Hope this helps >> >> -éric > > _______________________________________________ > spring mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/spring _______________________________________________ spring mailing list [email protected] https://www.ietf.org/mailman/listinfo/spring
