[c-nsp] igmp snooping inside 802.1q trunks

bisnsp at googlemail.com bisnsp at googlemail.com
Thu Feb 2 08:55:29 EST 2006

On 2 Feb 2006, at 01:01, Tim Stevenson wrote:

> At 03:57 PM 2/1/2006, Tim Stevenson submitted:
>> Not sure what to conclude based on that information.
>> Flooding will happen in a few cases that occur to me:
>> * IGMP snooping disabled
>> * the port is learned/configured as a mrouter port
>> * no querier present in the vlan (you can get unpredictable behavior
>> here, snooping is not supported unless there is a querier)
> On second thought, I can't really think of a flooding case here - the
> common case is flaky membership (join state not refreshed for  
> example).

Hello TIm,

can you please clarify this point? I always assumed that IGMP  
snooping does not
work without a querier (mcast router) present on the LAN.
Am I wrong in this assumption?


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