Let's repeat the leaving query process again with a SSM.
The leave message is still a membership report message with the same
source and destination IP addresses and IGMP type.
It contains one group record with a new type we haven't yet seen.
In this case, the type is Block Old Sources,
which is the signal that the client wants to
specifically stop listening to a given source,
but not necessarily the entire group.
The group record contains one source address associated with group 232.3 .3 .3.
That source, 10.2 .5 .5, is the group that the client wants to tune out.
Any other join sources, such as 10.2 .5 .6,
remain active and will continue to deliver multicast traffic.
The group-specific query that is generated as a result of this Block
Old Sources membership report has some differences,
too.
As expected, the source and destination IP addresses,
IGMP type, and max response time are nothing new.
The group address carried in the IGMP data is the group in question,
232.3 .3 .3.
At the bottom, notice the number of sources is 1,
and the recently left source of 10.2 .5 .5 is included.
This is the router asking is anyone else still interested in
group 232.3 .3 .3 specifically from 10.2 .5 .5?
If any other clients on the LAN segment are interested,
they need to answer within 1 second with a membership
report specifically joining group 232.3 .3 .3 from source
10.2 .5 .5 using include mode.
Now that we've covered all of the IGMP versions,
let's briefly compare the newest two.
We've already seen the IGMPv2 RFC and now I'll show the IGMPv3 RFC
in case any viewers want to research further.
IGMPv2 and earlier issued 1 IGMP membership report per group,
but IGMPv3 allowed these updates to be batched in 1 message using group records.
IGMPv2 only supported any source multicast requiring PIM
rendezvous points to exist while IGMPv3 provides the option
for source-specific multicast, simplifying many multicast deployments.
IGMPv2 introduced the leave group message,
which was a big improvement over IGMPv1,
but IGMPv3 recycled existing resources to signal disinterest in
groups using include mode with no sources.
We will be jumping into IPv6 next,
so be sure you've got the IPv6 basics down before continuing. See you in the next module!