This module introduces IPv6 multicast and 1 of its core protocols,
multicast listener discovery.
Many companies have already deployed IPv6 and even
more are in the process of doing so.
I trust this knowledge is relevant for almost everyone, so let's get started.
Okay, it's time for some fun.
IPv6 multicast isn't really hard, but as you'd expect,
it has a few interesting points.
IGMP has been replaced with multicast listener discovery,
or MLD, and we will begin exploring version 1 of the protocol.
In order to master MLD, we need to see it in a live network complete with debugs.
We will tear apart the resulting packet captures from that demo to wrap up.
There are a number of differences in IPv6 multicast compared to IPv4 multicast.
IPv6 uses the FF00::/8 range for multicast addressing.
A simple rule is that anything starting with FF is multicast.
In IPv4,
you could manually configure multicast boundaries to scope certain
multicast groups within some administrative domain.
With IPv6,
this information is carried as the fourth hex digit in the multicast group,
the x on the slide.
This simplifies group containment administration.
I'll provide a quick reference chart on the next slide.
Both any source and source-specific multicast varieties are supported with IPv6.
The SSM range is FF30::/32, comparable to 232.0 .0 .0 /8 for IPv4.
Here's a table of the multicast scopes for reference.
Pause the video if you'd like to read it.
The main takeaway is that lower numbers have narrower scope
and larger numbers have broader scope. I'll explain the relevant scopes as we see them, so don't memorize them.