[AUDIO LOGO]
Our first option to look at for discovering the RP
is simply to statically configure
the RP on each router in the environment,
including the RP itself.
Now, static configuration is often
looked down upon as something we don't really
want to have to do.
And it certainly does have advantages and disadvantages
like most other things.
However, this can actually be a fairly viable solution
in a lot of environments, particularly
if we combine this with something
called Anycast RP that we'll be looking
at in just a few videos.
So although static RP by itself probably
isn't a great choice in a lot of environments,
it can be when combined with other features.
So let's go ahead and jump in and take a look
at some of those advantages and disadvantages.
And then we'll look at how to configure it
on the command line.
So looking at static RP configuration,
let's go over some of its advantages and disadvantages.
So one of its advantages is this is actually
going to be very, very simple configuration.
We simply have to enter one command on each device,
telling it where the RP is, and that's it.
That's all there is to configuring static RP.
It really doesn't get any easier than that.
Now, a downside is we can actually only
have one RP configured at a time.
Now, as I said during the introduction,
there are other ways to provide redundancy.
But static RP itself does not have a method
built in for redundancy.
We can configure one RP.
That's it.
That's the one it uses.
And if that RP is not available, well, then sparse mode
is not going to function.
Another downside here is this can
be rather tedious to configure on all the routers.
Clearly, that depends on how large your environment is.
But the good news here is in most
larger environments where this would become a problem, well,
usually, we're going to have some sort of management
software that actually can ease the deployment
of these commands by sending it out
to multiple devices at the same time.
So a small environment, this isn't really
going to be that tedious anyway.
A large environment, you're going
to have some sort of network management software.
It's really the networks in the middle
where this can be a little bit tedious.
And along with that, if the RP address ever changes,
all those routers are going to have to be reconfigured,
which could take us right back up to this problem
where it might be tedious.
But, hopefully, we have some of that management software
to help take care of this for us.
And one last point, as we mentioned
during the introduction, we can combine this
with something called Anycast RP, which
we'll be looking at shortly.
But this can be used to add redundancy, mobility,
geographic load sharing.
We'll talk about all those in detail
when we get to Anycast RP.
But the idea behind Anycast is we
have just one address that provides
all of these services we just talked about.
Then our static RP configuration can simply
point to that one address.
That address can have redundancy.
It can be moved, and it can do geographic load sharing.
So that's the idea here.
We use this one Anycast address.
And then our static RP configuration
points to that one Anycast address.
And it works together quite nicely.
So with all of these advantages and disadvantages out
of the way, let's actually just jump into the command line
and see how we would configure static RP.
So for this demonstration, we're just
going to use a single router here, router 1.
And let's start with a show IP pim rp map.
As we can see, we currently have no rendezvous points
mapped to any multicast groups, which by the way,
is because router 1 is currently unconfigured.
This, of course, is what we're here to configure.
Let's also do a show IP pim rp.
And what we see here is there are currently
no RPs configured.
So this is what we would be expecting
from a nonconfigured device.
So let's go into configuration mode.
First thing we want to do is enable multicast
routing on this device.
This device is running IOS XE.
So the way we do that is we say ip multicast-routing.
And then we can either enable it for a particular VRF,
or we can just say distributed, and it
will enable the multicast routing for the whole platform.
Next, we'll configure an interface.
So let's just do interface gigabit 1.
It's going to need an IP address.
We'll just give it something like 192.168.12.1.
We'll make it a /24.
And let's enable sparse mode.
So we'll say IP pim sparse.
Let's bring that interface up.
Then let's create a loopback that we'll
use for our rendezvous point.
So we'll say interface loopback 0.
We'll say IP address 10.1.1.1.
And we'll make that a /32.
We'll enable PIM sparse mode.
And let's exit interface configuration.
So now let's do our show ip pim rp map again.
As you can see, we, of course, still
don't have an rp map, because all we've done
is enable multicast configure, a few interfaces,
and enable PIM sparse mode.
But we still need a rendezvous point.
The command for this is simply to say ip pim rp address
and then put in the address of the device.
So we can say 10.1.1.1.
That's the address that we want to be the rendezvous point.
We can see a couple options after this,
where we can actually use an access
list to control which groups this will be the rendezvous
point for.
It doesn't have to be the rendezvous
point for all of the groups.
So although this doesn't give us any form of what
we would normally call traditional load sharing where
the device does its own load sharing,
we could do some manual load sharing here
by taking some of our multicast groups,
sending them to one static address,
and then take different groups and send them
to a different IP address.
So, again, it won't do load sharing
in the traditional sense.
But it can do it manually if we choose
to configure it using these access lists to control
which groups are going to be controlled
by this particular RP.
Now, the other option to look at here is override.
Override can be used if we want to use the static entry over
automatically learned entries that we
learn from, say, AutoRP or BSR.
This is actually an odd situation
where the dynamically learned RPs will actually
beat the static RP unless you say override.
Now, we don't need to do that in this configuration.
So we'll just hit Enter.
But those are the options we would have on the static RP
configuration.
We also see here these tunnels coming up.
These are those PIM register tunnels
that we were talking about.
It's getting these tunnels ready for other routers
to be able to register their multicast sources with the RP
address.
So if we do our show IP pim rp map again,
what we see is that for the entire multicast group range,
because we didn't specify a group range,
we have a static entry that the RP is 10.1.1.1.
Now, you might have noticed there was a slight pause
while this command was running.
And notice in these parentheses we have a question mark.
The reason for this is the router
is trying to do a reverse DNS lookup on the 10.1.1.1
to come back with a friendly hostname.
Well, we could give it a friendly host name
and see what that looks like.
We'll just say ip host R1 is 10.1.1.1.
So if we give it this information-- now, of course,
normally, in an environment, we would probably
want to point this to a DNS server.
But just to show you how it works, if we do our show ip pim
rp map again, notice, first, no pause because, well, it's
local information.
It looked it up pretty much instantly.
But notice it's now putting the host name in the parentheses.
We'll see this a lot as we go through multicast.
A lot of these outputs will try to put the hostname along
with IP entries.
So that's really all there is to configuring static IP.
In this video, we took a look at configuring
static RP on the Cisco routers.
Now, we also talked about some advantages and disadvantages.
Again, this is fairly simple to configure.
I mean, we, again, put in one command on this router
aside from configuring some interfaces that
needed to be configured.
But there's not really anything to configuring this unless you
get into a large environment.
And then, of course, it could be a little bit tedious
to have to put this on all the routers.
Hopefully, we have some form of network management
to be able to handle that and help us with that project.
But other than that, static RP is a very simple option.
And combined with things like Anycast RP that we'll
be looking at later, this can actually
be a really good solution in the right environment.
Now, other choices are dynamically learning the RP.
And the first choice for dynamically learning the RP
is Cisco's AutoRP.
And that's exactly what we're going to take a look at next.
Until then, I hope this has been informative for you.
And I'd like to thank you for viewing.