I am a newbie to the networking and working on the 6LoWPAN protocol and I am trying to get the multicasting to work on the network. But I don't know how to create group for multicasting and how to provide a group ID to the device which wants to join the multicast group.
closed as not a real question by Falcon Momot, Ward♦, Wesley, Scott Pack, Cian May 26 '13 at 2:05
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Broadly, when you want to use IPv6 multicast, your hosts can simply join multicast groups ad-hoc by sending an MLPv2 ICMPv6 message (RFC3810) to the multicast routers multicast address FF02::16. If you are using 6LoWPAN to build a mesh network, I believe all your devices would also need to support MLPv2 as routers as well as hosts.
Without knowing more about your platform and what exact task you are trying to accomplish, this is as far as I can take you. I don't believe there is a de facto standard utility set for this in linux, and if you're developing an embedded device either your platform will have an API for this or you will have to implement it from the RFC.
Multicast groups are created implicitly when a host joins one, and the multicast address functions as a group ID. These are fundamental intrinsics of the design of IP multicast.