[AUDIO LOGO]
So now it's time to jump onto the command line
and actually configure our IS-IS environment to support IPv6.
Now as we jump in here, we're going
to see that this is just as easy as enabling the address
family under the interfaces and the process.
So we'll take a look at this in iOS XR as well as iOS XE.
So once again, let's bring up our topology
real quickly just so we have an idea of what's going on.
And then we'll jump into the command line
and get IPv6 configured for IS-IS.
So for this demonstration, we'll again
be on IS-IS IPv6 6 Topology 1.
And we're going to be using the same basic area
structure that we used in our IPv4 skills.
However, clearly, these are now running IPv6 addresses.
We want to look at our configuration on both iOS XR
and iOS XE.
So we're just going to focus here
on looking at the configuration on router 1
which, of course, is running iOS XR,
and then also on router 6, which is, of course, running iOS XE.
So let's jump into the command line
and get IS-IS configured for IPv6 support.
We'll start on router 1.
So let's begin here on router 1 with a show IPv6
interface brief just to verify which interfaces
are, in fact, running IPv6.
Now here's the interesting thing about configuring IPv6 support
in IS-IS.
We have to go into configuration mode, of course.
We go into router IS-IS 1.
We go into our loopback interface, for example.
This is our first interface we have that's running IPv6.
And we simply say, address family, IPv6 unicast.
That's it.
That's all we have to do.
We then go into our other interfaces,
and we enable the address family for those as well.
So we need gigabit 0, gigabit 1, and gigabit 3.
We'll commit our changes, exit configuration mode.
And we can verify by saying, show protocol IPv6.
And what we see here is that, IS-IS
is, in fact, enabled for IPv6.
So there's really nothing more to configure in IS-IS,
then enabling this additional address family.
We can also see here on iOS XR, since it's
listing these different topologies,
that iOS XR actually defaults to multitopology support.
So now let's go configure router 6.
The first thing we see on router 6
here is, it's already complaining about its adjacency
to router 1 because the topology has changed,
but this router doesn't support that.
So the first thing, of course, we're going to have to do,
we'll go into our interfaces and simply do IPv6 router IS-IS 1.
This is how we enable this on iOS XE.
Again, we need interface gigabit 1 also here on router 6,
and then we can exit out of configuration mode.
Now for some verification, let's do a show IPv6 protocol.
We see here that IPv6 routing is enabled
for BGP 100 as well as IS-IS 1.
And we see that it's configured for our loopback
0 and our gigabit 1 interface.
So so far, this is looking good.
Let's do a show CLNS protocol.
We see here that both of our interfaces
are supporting IP and IPv6.
If we do a show IS-IS neighbor, we
see that we have a neighborship with router 1 and router 7.
If we do a show IP route IS-IS, we
see that we still have all of our IPv6 four routes.
And if we do a show IPv6 route IS-IS,
we see that we don't have anything.
So we have neighborships, but we're not learning any prefixes
from IPv6.
Now the reason for this might not be quite so obvious,
but we did see some hints.
We saw that iOS XR defaults to multitopology.
It was listing two different topologies.
IOS XE on the other hand, does not.
It defaults to single topology.
And if you remember in one of our previous videos,
we mentioned that the adjacencies will not
come up if we don't match on the topologies.
Now the neighborship itself comes up.
But as you can see, we're not properly exchanging databases.
So let's change router 6 to be multitopology.
This is a real easy fix.
We just have to go back into router IS-IS 1.
And under address family IPv6 unicast, all we have to say
is multitopology.
We'll exit out of our configuration.
We'll do a show IPv6 route IS-IS.
We see that now we're learning routes from router 1.
We can verify this on router 1 side as well.
Here we'll say, show IS-IS neighbor detail.
And we see right here towards router 6
that it actually supports IPv4 unicast and IPv6 unicast
topologies.
As one final test, let's make sure we have reachability.
So let's ping-- router 6 is loopback.
It's 2001.
Colon db8.
Colon 10.
Colon, colon 6.
And we will source that from our loopback interface as well.
We see that this is successful.
So we know we have routes in both directions.
As one final check, let's go look at the IS-IS hellos
in Wireshark.
So right here at packet 1, we have an IS-IS Hello.
So let's go ahead and take a look
at the detail in the IS-IS Hello.
If we expand the IS-IS Hello, scroll down a little bit,
a couple of things to note.
First, under protocols supported,
if we open this field, we see that it's
supporting both IP and IPv6.
And we see those values of 0xcc and 0x8e corresponding
to those NLP IDs.
Also, if we scroll down, we also see here our traditional IPv6
for interface addresses at a type 132.
Right below this, we see the IPv6 interface
addresses at a type 232.
And we also see that this is carrying
the multitopology information TLV.
So here we can see all of this information being
carried on the wire.
In this video, we saw how to configure
IS-IS to support IPv6.
And given that we already have our IS-IS structure built
as far as areas, and net numbers, and all of that,
this is just as easy as enabling the address
family under the appropriate interfaces.
As such, I'm not going to take us
through every single interface on every single router that
needs to be configured.
I'll configure those offline.
And then in the next video, we're
just going to take a look at how to do some summarization
and redistribution with IPv6 in IS-IS.
All of the routers will already be configured for IPv6.
I hope this has been informative for you,
and I'd like to thank you for viewing.