[AUDIO LOGO]
So now it's finally time to jump in and set up SSM.
Now, this is going to be incredibly easy.
But before we get that far, let's just
have a reminder that we have already
enabled multicast routing on our devices,
and we have already enabled PIM sparse mode
on all of our interfaces.
So, that does have to be done first.
That, of course, is a prerequisite,
but all we have to do now is specify either the default
group or another group that we want to use for SSM,
enable the feature on the devices
and then just start up our source and our receiver.
So, let's go ahead and jump in.
Look at the topology just so we have an idea
of what's going to happen.
And then, of course, we'll jump into the command line
and make all of this happen.
So we are still on Multicast Topology 2, and let's talk
about what's going to change.
The first part is router 2 is no longer going
to be a rendezvous point, and router 5
is no longer going to be a BSR.
Now, this part I've already configured just
in the interest of time.
So, the rendezvous point and the BSR
have already been completely removed from the environment.
The next thing we're going to do is simply
look at what happens when router 8 joins our group using
a specific source.
Now remember that router 10 up here is
our source going to 224.1.1.1.
So when router 8 specifies the source,
it's going to be router 10's address on this subnet.
So it's going to be the 50.2.61.10
because that's where router 10 is actually
sourcing its traffic from.
So that's what we'll be specifying as the source
address.
And since we're still using our group, 224.1.1.1.
This means that we are not using the default group 232.0.0.0/8.
So we'll have to use an access list to specify
the group that we're using.
So that's going to make it a little bit more complicated,
but you'll see not very much.
Let's go ahead and jump into the command line,
and get all this up and running.
OK.
So the first thing we want to do is verify
that we have no RP in the environment.
So we'll just use our chat window here.
We'll do a show ip pim rp map.
And all of the devices should be showing this as empty.
So we can see here that router 1 has no RP.
Router 2 doesn't.
Nothing on router 3, router 4, router 5, router 6,
and router 7.
None of these have an RP.
There's no in the environment.
The next thing we want to do is go ahead and start up
our source.
So let's jump over to router 10 and get our source running.
So we'll go ahead and start up our ping.
So now, we have our source running.
And then let's look at what happens on the first hop
router.
Remember the job of the first hop router
is to register a source with the rendezvous point,
but there's no rendezvous point.
So let's jump over to router 6.
And let's do a show ip mroute.
Notice that it has nothing accept the default entry
for auto RP, which is always going to be there.
With no RP, PIM Sparse mode has no idea what to do.
This isn't going to make it past the first hop router
even though the source is up and running.
But that's OK because we're here to configure SSM.
Now, we are configuring SSM without using the default group
range, so we have to take one extra step
that we wouldn't normally have to do if we
were using the default range.
We're going to have to create an access list so
that all of the devices know which groups are using SSM,
and therefore, not to try to use a rendezvous
point for those groups.
That's why we have to tell the routers which ones are SSM.
So let's start over on router 1 since we
have to configure this access list on all of the routers
anyway.
We'll simply go into configuration mode.
We'll make an IP access list.
All we need is a standard access list.
Let's call it ACL_SSM_GROUPS.
And all we have to do here is permit whatever groups
that we want to be part of SSM.
So we'll just do for example 224.1.1.0/24.
So we'll just use a wildcard mask like this.
And now, all of the groups, 224.1.1.0/24,
will be SSM members.
Now what we have to do is enable SSM.
So we say, ip pim ssm.
And then we have two choices.
As you can see, if we were using the 232/8,
we would literally just type default here.
And then you can see all at once is for us to hit Enter.
See, we wouldn't need the access list.
We would just type, ip pim ssm default. Enter.
Done that's it.
But since we're not using the default range,
we have to say range and then we have to specify our ACL.
So ACL_SSM_GROUPS.
All we have to do is put our ACL and that command
on all of our routers.
Since it's going to be standard on all of the devices,
we'll just copy and paste it in.
So we'll put it on router 2, router 3, router 4, router 5,
router 6, and router 7.
That's it.
That's all we have to do to configure SSM
except on the client side.
On the client side here on the last hop router,
there is one more thing we're going to have to do.
If we say, do sh ip igmp interface,
we'll specify gigabit 3.
That's what's facing router 8.
Notice that the current IGMP host version is version 2.
And as we've said, we want version 3
to be able to support SSL.
So we have to go into Interface Gigabit 3.
And again, this would be all interfaces facing clients.
And we simply have to say, ip igmp version 3.
If we look at our interface again,
notice that now the current IGMP host version is now version 3.
We can exit configuration here.
But remember that our client will need that as well.
So over to router 8.
So we'll simply go into configuration mode
into Interface Gigabit 1 and say, ip igmp version 3.
So now we've created our ACL.
We've enabled PIM Sparse mode for that group range.
And now, we've configured IGMP version 3 between the client
and the last hop router.
That means we're ready to fire up SSM.
So all we have to do is join the group on the receiver
with the correct source.
Let's go ahead and do that and see if it works.
So we simply say, ip igmp join-group.
Of course, we're still joining the 224.1.1.1.
However, here's, of course, the big change.
We're going to specify the source.
The source is router 10.
So that's 50.2.61.10.
We'll go ahead and hit Enter, and let's see
if this is working.
If it worked, we should have mroutes on our devices now.
So let's go see what's going on router 7.
We'll do our, sh ip mroute, and look at that.
Right there is an S comma G entry.
The flags on it are S, T and I.
The S indicates that it's an SSM group.
The T, of course, means that it's the SPT or the Shortest
Path Tree.
And the I means that we received this source information
from a source specific host report.
Meaning, IGMP version 3.
If we do this again with our count,
we can see that it's currently forwarded 14 packets.
And if we hit up again, we can see that now it's forwarded 19.
So it's definitely forwarding traffic.
And our source specific multicast is working correctly.
Just to look on a few more routers, if we
were to say hop over and look at router 1, notice,
it is also aware that this is an SSM group
with that lowercase s flag.
And of course, it's the Shortest Path Tree.
So no star comma G entries.
Only S comma G entries.
And just like that, we have SSM up
and working in our environment.
So in this video, we saw just how easy
it is to configure SSM even when we're using a non-default group
range.
All we had to do was create an ACL to identify the groups
that we want to be source specific multicast,
enable the feature on all the routers,
enable IGMP version 3 at the edge,
and then start up our source and receiver.
That's it.
Just like that, SSM comes up and works,
but there is one more scenario that we need to look at.
What if the client, in this case, router 8,
doesn't actually support IGMP version 3?
Well, there's a way we can fix that too,
and that's exactly what we're going to look at next.
Till then, I hope this has been informative for you,
and I'd like to thank you for viewing.