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I've been reading Allied Telesis' guide on configuring IGMP, which has been quite enlightening so far. However, I'm still wondering whether the IGMP querier has to be connected directly to the multicast source, as it is shown in the example below?

IGMP example

What would happen if the multicast server was not directly connected to the IGMP querier — would the switches forward multicast packets to the querier? Would all multicast packets have to pass through the querier, even if that is not the shortest path?

eWolf
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In the file you gave a link in your question (http://www.alliedtelesis.es/media/fount/how_to_note_alliedware/howto_config_igmp1.pdf) it is stated that choosing the closest switch to the multicast source is the best practice but it is not essential. On page 15 there is an example of the net where another switch rather then the closest is chosen as querier. According to description of IGMP after determination of querier multicast packets will go through it even if it is not the closest path.

Meriadoc Brandybuck
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