> > > The behavior you describe sounds correct. IGMP snooping depends on IGMP > traffic in order to have something to snoop. Without an IGMP querier, you > can only count on the initial (unsolicited) IGMP host report. There might > be no other traffic, rendering IGMP snooping is totally helpless. It makes > sense that traffic would flood to all ports until you enable a querier. > This sounds like a feature: The switch is smart enough to disable > multicast filtering when the information required for good decision-making > isn't available. > > ok - i follow - makes sense, thanks
> > If I remove 'ip igmp snooping querier', and configure 'ip pim sparse- > > mode' on an SVI in that vlan, again I would expect the 3560 to stop the > > flooding, but the flooding goes on an on, which i dont expect. > > Is 'ip multicast routing' enabled? What does 'sho ip igmp snooping > querier' have to say about it? > > must have been an isolated issue, perhaps due to "multicast routing", as it worked fine on another 3560 ! > > On the 4948, flooding again does occurs with default config with igmp > > snooping enabled by default, but different to the c3560 both 'ip igmp > > snooping querier' and/or 'ip pim sparse-mode' take care of controlling > > that. > > Last time I needed 'ip igmp snooping querier', it wasn't available on the > 4948. What version are you running? > > yes its there on 12.2(50)SG6 now to troubleshoot why the CPU is at 99% due to high "IP Input" and "PIM Process" when i connected multiple sources and recievers..... somehow TTL=1 is a suspicion. -- Thanks, anton _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
