IGMP snooping functionality on apple time capsule & extreme

And I have an airport extreme as well which does not have IGMP snooping enable/disable functionality. How IGMP and multicasting works on this?

What model and firmware is the extreme?

If you look under the wireless options in the 5.6 utility it shows multicast as preconfigured to on.. and set to low by default. you had the option to set higher if you wished with the result that more of the wireless bandwidth was reserved to handle multicast.

You might need to use the older utility if it is Gen5 or earlier as some functionality was simply removed in the v6 airport utility and never returned.

IGMP never rates a mention.

On wire-shark, I can see an IGMP query message is going out of apple capsule on enabling "IGMP snooping" and there is no IGMP query message from apple capsule when IGMP snooping is disabled. Based on IGMP V3 standard, a IGMP query is sent by router. On "IGMP snooping" disabled case, is it host's responsibility to forward multicast packets?

I cannot answer your specific question.. but is the IGMP set on by default?? If so I expect apple was thinking it should automatically handle the bandwidth demand whereas the older ones had issues with this and needed manual setting when using wireless. If you turn it off then multicast will have issues I am guessing.

One place you can usually find some info is to export the configuration.

Then do a search.. it is an xml file. Although it will be name.baseconfig

I can see no mention of it in a file from older extreme.. it simply never had a setting for IGMP.

Bob told me my picture above was not displaying so here is another one showing the huge range of options you have.