Gyan, Your below email nicely proves my point. Unequal cost load sharing is done at the app level not IGP transport.
Thank you, R. On Thu, Jan 13, 2022 at 2:26 AM Gyan Mishra <hayabusa...@gmail.com> wrote: > > Robert > > Here are a few examples of UCMP drafts below used in core and data center > use cases. > > https://datatracker.ietf.org/doc/html/draft-ietf-bess-evpn-unequal-lb-15 > > https://datatracker.ietf.org/doc/html/draft-mohanty-bess-weighted-hrw-02 > > https://datatracker.ietf.org/doc/html/draft-ietf-idr-link-bandwidth > > https://datatracker.ietf.org/doc/html/draft-mohanty-bess-ebgp-dmz > > > > There are many use cases in routing for unequal cost load balancing > capabilities. > > Kind Regards > > Gyan > > On Wed, Jan 12, 2022 at 2:23 PM Robert Raszuk <rob...@raszuk.net> wrote: > >> Linda, >> >> > IGP has been used for the Multi-path computation for a long time >> >> IGP can and does ECMP well. Moreover, injecting metric of anycast server >> destination plays no role in it as all paths would inherit that external to >> the IGP cost. >> >> Unequal cost load balancing or intelligent traffic spread has always been >> done at the application layer *for example MPLS* >> >> Thx a lot, >> R. >> >> On Wed, Jan 12, 2022 at 8:18 PM Linda Dunbar <linda.dun...@futurewei.com> >> wrote: >> >>> Robert, >>> >>> >>> >>> Please see inline in green: >>> >>> >>> >>> *From:* Robert Raszuk <rob...@raszuk.net> >>> *Sent:* Wednesday, January 12, 2022 1:00 PM >>> *To:* Linda Dunbar <linda.dun...@futurewei.com> >>> *Cc:* Les Ginsberg (ginsberg) <ginsb...@cisco.com>; lsr@ietf.org >>> *Subject:* Re: [Lsr] Seeking feedback to the revised >>> draft-dunbar-lsr-5g-edge-compute >>> >>> >>> >>> Hi Linda, >>> >>> >>> >>> *[LES:] It is my opinion that what you propose will not achieve your >>> goals – in part because IGPs only influence forwarding on a per packet >>> basis – not a per flow/connection basis.* >>> >>> *[Linda] Most vendors do support flow based ECMP, with Shortest Path >>> computed by attributes advertised by IGP.* >>> >>> >>> >>> I am with Les here. ECMP has nothing to do with his point. >>> >>> >>> >>> [Linda] Les said that “IGP only influence forwarding on a per packet >>> basis”. I am saying that vendors supporting “forwarding per flow” with >>> equal cost computed by IGP implies that forwarding on modern routers are >>> no longer purely per packet basis. >>> >>> >>> >>> >>> >>> Draft says: >>> >>> >>> >>> *When those multiple server instances share one IP address (ANYCAST), >>> the transient network and load conditions can be incorporated in selecting >>> an optimal path among server instances for UEs.* >>> >>> >>> >>> So if we apply any new metric to indicate load of a single anycast >>> address how is this going to help anything ? >>> >>> >>> >>> [Linda] The “Load” or “Aggregated Site Cost” is to differentiate >>> multiple paths with the same routing distance. >>> >>> >>> >>> >>> >>> You would need a mechanism where the network is smart and say per >>> src-dst tuple or more spreads the traffic. IGP does not play that game >>> today I am afraid. >>> >>> [Linda] There is one SRC and multiple paths to one DST. IGP has been >>> used for the Multi-path computation for a long time. >>> >>> >>> >>> Thank you, Linda >>> >>> >>> >>> Thx a lot, >>> R. >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >> _______________________________________________ >> Lsr mailing list >> Lsr@ietf.org >> https://www.ietf.org/mailman/listinfo/lsr >> > -- > > <http://www.verizon.com/> > > *Gyan Mishra* > > *Network Solutions A**rchitect * > > *Email gyan.s.mis...@verizon.com <gyan.s.mis...@verizon.com>* > > > > *M 301 502-1347* > >
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