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Re: IPv6 w.g. Last Call on "IPv6 for Some Second and Third Genera tion Cellular Hosts"



>So when is MLD needed? I will copy a paragraph from
>the intro of 2710:
>
>   "The purpose of Multicast Listener Discovery (MLD) is to enable each
>   IPv6 router to discover the presence of multicast listeners (that is,
>                  --------------------------------------------           
>   nodes wishing to receive multicast packets) on its directly attached
>   links, and to discover specifically which multicast addresses are of
>   interest to those neighboring nodes.  This information is then
>   provided to whichever multicast routing protocol is being used by the
>   router, in order to ensure that multicast packets are delivered to
>   all links where there are interested receivers."
>
>Note the underlined text. If no discovery is needed, because
>the addresses are hard coded, then no MLD needed for those 
>addresses. 
>Makes sense?

	no, it doesn't make sense to me.  even for hardcoded addresses, there
	should be an MLD join packet issued from the listener.

	what i don't understand is why you are wanting to omit it.  for
	example, if 3G mobile node in the following diagram transmits MLD join,
	uptream router could suppress packet to the expensive wireless link for
	packet to ff02::blah.  i believe MLD support has benefit to the
	situation.

itojun


	router
	  |
	  |
	3G mobile node
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