Like IGMPv3,
MLDv2 manages to offer a completely new way to think about multicast,
except this time in the IPv6 world.
Stick around to learn how it works.
Here's the lineup for this module.
MLDv1 was a solid protocol, and it worked pretty well,
but as we learned with IGMPv2 and IGMPv3,
there is room for improvement.
Believe it or not,
source-specific multicast support in IPv6 is even more important than in IPv4.
I'll explain why shortly.
We will reload our demo for a detailed MLDv2 test to see how the protocol works.
During our demonstration,
we will generate the necessary MLDv2 traffic for a detailed Wireshark analysis.
I spoke about the complexities of interdomain multicast in the IGMPv3 module,
but I want to revisit it here.
I'm not going to rehash minor MLDv1 problems,
since it would be far too repetitive.
The protocol used to interconnect rendezvous points in IPv4,
known as MSDP, does not exist in IPv6.
Generally speaking, there must only be one RP for a given multicast group.
Now what?
One solution is to use the scopes we discussed in the previous module.
With each domain, one RP will serve all site local scoped groups using scope 8.
Then,
globally there will be one RP for a subset of the
globally scoped groups using scope E.
Conceptually it sounds easy, but administration and coordination,
not to mention security and trust, make this solution unfeasible.
Again, what if the client knew the global multicast sources ahead of time? Wouldn't that be easier?