I try to understand why certain multicast packets coming from sources are being forwarded even thought there is no route towards the source.
To be more precise: rtr# sh ip mroute 239.255.255.250 count IP Multicast Statistics 100 routes using 81502 bytes of memory 18 groups, 4.61 average sources per group Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per second Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc) Group: 239.255.255.250, Source count: 9, Packets forwarded: 2490727, Packets received: 2492613 RP-tree: Forwarding: 804794/0/292/0, Other: 806652/1846/12 Source: 192.168.0.1/32, Forwarding: 0/0/0/0, Other: 19/19/0 Source: 169.254.114.143/32, Forwarding: 0/0/0/0, Other: 0/0/0 Source: 10.57.48.7/32, Forwarding: 4/0/369/0, Other: 4/0/0 Source: 10.57.48.8/32, Forwarding: 4/0/369/0, Other: 4/0/0 Source: 10.57.48.6/32, Forwarding: 4/0/369/0, Other: 4/0/0 Source: 10.57.48.10/32, Forwarding: 4/0/370/0, Other: 4/0/0 For some reason the packets coming from the 10.57.48.x sources are forwarded but not the ones coming from 192.168.0.1. The routes towards the sources don't exist in our network - at least not in the routers I can access. There is default route on every router pointing eventually to our upstream but I trust our upstream to have set up their routing properly and not to forward such backets. I explanation I can think of that one of the routers I cannot control sends PIM Register packets to RP and from there the info is propagated to other routers. That might explain also why the RPF check fails on every other router except the RP. But it makes me wonder why RP still forwards the packets. Does this sound reasonable explanation? I didn't refresh my knowlegde on the PIM SM details so I have quite likely misremembered something. Cheers, Matti _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
