Yes please what I meant was router wouldn't need to wait for IGP to compute the RPF interface -as that would already be in place as LFA -so the router can send Join out that interface immediately
Since you mentioned it already -are there any plans for sort of IP FRR for m-cast please? -where each node would pre-compute a backup Incoming Interface for every primary IIF and backup OIL on each m-cast state -but this would require link-state protocol in place of PIM adam -----Original Message----- From: Oliver Boehmer (oboehmer) [mailto:[email protected]] Sent: Monday, June 25, 2012 2:32 PM To: adam vitkovsky; [email protected] Subject: RE: [c-nsp] fast multicast convergence > > > it will send a join after a new RPF intf. has been identified for a > > given > source. > > I see, so if I'll run IP FRR/LFA it will be almost immediately right please? well, no, IP-FRR/LFA will not protect multicast traffic (at least not yet), RPF interface update needs to follow "regular" IGP convergence, so in sub-second (rather than 50 msec or so). If you need FRR-type of convergence for Mcast, you need MoFRR or p2mp-RSVP-TE with TR-FRR. > >IIRC, there is/was some interdependency with pim query-interval and > >link-up > > I see, so I'll definitely need to make sure my IGP adjacency to come > up before the PIM neighborship is established on a given link actually not: The problem is (or better was, I think we fixed it) that the first PIM hello could get dropped following a link-up as the neighbour might not have been ready. Then we needed to wait for the query-interval to pass to send the next hello. But by then IGP was alrady up and has converged, so the RPF interface was changed, but we couldn't send a PIM-Join over the new interface as PIM hasn't come up yet. That was the issue, if I got that right.. > I don't really see any advantage in tuning the PIM > query-interval(which affects hellos) on the p2p links between routers > because when the link goes down the PIM neighbor is removed > immediately ack, the problem above is only for the up event. Down-event is handled by the interface (or by IGP), but IOS-XR also enables BFD for PIM. > I guess the longest delay is introduced when the links at router > connected to source fails -as the routing change needs to be > propagated via IGP -than it all boils down to how well is the IGP > tuned for fast convergence well, I guess this is true for all link failures in between source and dest, or why do you point to the first-hop router? oli _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
