Hi, Robert: The two cases I listed for requiring the individual loopbacks were the ones we faced at InternetMCI many years ago when we were investigating using both L2+L1 (prior to L2 route leaking). It's not sufficiently accurate to rely on the aggregates in these cases.
Thanks. -- Enke On Fri, Oct 15, 2021 at 10:37 AM Robert Raszuk <[email protected]> wrote: > Enke, > > Not really ... unless you force it by configuration most specific route is > used to resolve your next hops. > > Clearly everything works fine from your list with no loopbacks everywhere > - except summary route is used instead. > > Best, > R. > > > On Fri, Oct 15, 2021 at 7:21 PM Enke Chen <[email protected]> > wrote: > >> Hi, Folks: >> >> As I recall, the loopbacks and their metrics need to be propagated >> individually to the whole network (including leaking from Level 2 to Level >> 1) for the following reasons: >> >> 1) Path selection: in case there are multiple Level 2 / Level 1 routers >> in an area. >> 2) Export IGP metric : when the IGP metrics are exported to BGP as MED >> for symmetric routing. >> >> Not sure if there is still a problem to be solved. >> >> Regards, >> >> -- Enke >> >> ---------- Forwarded message ---------- >> From: Tony Li <[email protected]> >> To: "Les Ginsberg (ginsberg)" <[email protected]> >> Cc: Gyan Mishra <[email protected]>, lsr <[email protected]> >> Bcc: >> Date: Wed, 13 Oct 2021 22:50:33 -0700 >> Subject: Re: [Lsr] "Prefix Unreachable Announcement" and "IS-IS and OSPF >> Extension for Event Notification" >> >> Les, >> >> If you’re advertising loopbacks that are outside of the summarized space, >> then you end up with reachability and liveness. Yes, there’s a cost in >> scalability… it ain’t free. >> >> Tony >> _______________________________________________ >> Lsr mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/lsr >> <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ietf.org_mailman_listinfo_lsr&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=OPLTTSu-451-QhDoSINhI2xYdwiMmfF5A2l8luvN11E&m=CyuvZoeTxWdq-MzY_N3aRC3vN5iXMJzjHo_7TP5_S2U&s=aG7aHzcn05QWfjkWdJ4f05SYrO_kHYoA6h3LccwlysQ&e=> >> >
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