If a switch doesn't support multicast, are multicast packets simply flooded out all ports? This would allow multicast enabled hosts to at least still receive the multicast frames.

Follow up question. If a Router doesn't support Multicast, I presume multicast packets it receives are simply dropped?

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    All switches support multicast,, and multicast frames (mot packets) are flooded out every other switch interface, unless the switch supports IGMP snooping, but link-local multicast frames are supposed to be flooded regardless of IGMP snooping. Multicast routing is very different than unicast routing, and it is designed to prevent multicast packets from going where they are not wanted.
    – Ron Maupin
    Nov 19, 2021 at 21:35

1 Answer 1


Multicast is a special case of broadcast. If a switch does not have any specific handling for multicast (eg. igmp snooping), multicast traffic is simply broadcast, and floods to all ports.

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