- [Instructor] In this video, we want to take a look at EIGRP
for IPv6, so we can route IPv6 networks with EIGRP.
Now, when I first started working with the EIGRP
back in the 1990s,
at the university where I was working,
we had three routed protocols.
We had IPv4, we had Apple's AppleTalk
and we had Novell's IPX,
and EIGRP could route those three different protocols.
Well, these days we don't see much AppleTalk or IPX
but we do have a couple of protocols that we want to route,
and those are IPv4 and IPv6.
And we've already seen how to configure EIGRP for IPv4
and we can have that configuration
and then add on a configuration for EIGRP for IPv6.
And I emphasize that we're doing two parallel configurations
one for IPv6 and one for IPv6, and it will work that way.
However, in our next video
we're going to take a look at a different flavor of EIGRP,
it's called Named EIGRP.
There, instead of having an EIGRP for IPv4,
and then having EIGRP for IPv6,
we can have a single EIGRP virtual instance,
one hierarchical configuration that contains everything.
But we'll check that out in the next video.
For now, let's focus on EIGRP for IPv6.
One thing I want you to know about this
is that when we look at our neighbor's identity,
when we say, "What's our next hop to get somewhere?"
Well, our neighbors going to show up as a link local address,
not a unicast address.
And we talked in a prior video
about EIGRP's ability to do auto summarization,
well there is no auto summarization with EIGRP for IPv6.
Something else that's different is that our EIGRP neighbor
does not need to be on the same subnet as we are.
And updates with EIGRP for IPv4,
they were sent to a multicast address of 224.0.0.10,
while with EIGRP for IPv6,
updates are sent to the multicast address of FF02::A.
FF tells us that this is an IPv6 multicast address,
the 02 tells us the scope, how far is this going to go,
and the A, that's the hexadecimal representation
of the number 10.
So both IPv4 and IPv6 flavors of the EIGRP,
they both end in a 10.
224.0.0.10 and FF02::A,
where A in hex equals a 10 in decimal.
Now let's go out to a live interface
and configure EIGRP for IPv6.
Let's configure EIGRP for IPv6 on these three routers.
Beginning on a router R1,
let's go into global configuration mode,
and we have to tell the router
to support IPv6 unicast routing.
It does not do it by default.
Now let's start the EIGRP for IPv6 routing process.
Now for IPv4, we could say,
router EIGRP one for autonomous system one.
Here we need to say IPv6 router EIGRP one
for autonomous system one.
And if we take a look at our context sensitive help,
we see common things we can do here,
like setting the variance, setting the passive interface.
However, there's one thing that is conspicuously missing,
the network command.
We don't have a network command
as we did with EIGRP for IPv4.
Now, with EIGRP for IPv4,
the network command specified an IP address space.
And if we had any active interfaces
whose IP addresses fell within that address space
then those interfaces would participate in the EIGRP,
meaning that we would advertise the networks
on which those interfaces resided.
However, we don't do that with a network command here.
Instead, we go directly into those interfaces
and we explicitly tell those interfaces
"Hey, I want you to participate
in this IPv6 EIGRP autonomous system."
To begin with, let's go into interface,
gigabit zero slash one,
and we'll say, IPv6 EIGRP autonomous system one.
We go into interface gigabit zero slash two
and we give an identical command.
That's it.
We're done with our configuration on R1,
let's hop over to router R2
and give, really, an identical configuration.
We go into global configuration mode.
Once again we say we want to support unicast routing,
IPv6 router EIGRP one, to begin the EIGRP routing process.
Then I go into interface gigabit zero slash one
and say, "I want you to be a part of this process."
IPv6 EIGRP autonomous system one,
same thing for gigabit zero slash two.
Oh, notice we just had an adjacency come up with R1,
that's good news.
Let's say once again, IPv6 EIGRP one,
and we're done with our configuration on R2.
Let's do the exact same thing on R3.
In global configuration mode, we say IPv6 unicast-routing.
Let's start the routing process
by saying IPv6 router EIGRP one.
And we go into those interfaces once again,
gigabit zero slash one, IPv6 EIGRP autonomous system one,
interface gigabit zero slash two.
Oh, we had another neighborship come up, great news.
And we say, "I want you to participate as well."
And we are done with our configuration.
Now that we've done that
let's give some verification commands.
Here on R3, I'm going to say,
show IPv6 route, instead of show IP route.
'Show IPv6 route' shows that
I have learned a couple of routes via EIGRP for IPv6.
Here we have 2000:1::/64.
That's the network off the top of R1.
Next we have 2000:2::/64,
that's the network between R1 and R2,
and here on R3, we're connected to the other two networks
in this topology.
So we should have full reachability throughout this network.
Let's test that. I can ping an IPv6 address.
Let's see if I can ping that top interface,
gig zero slash one, on R1.
Let's do a ping to 2000:1::1.
And that is successful.
We've got reachability throughout this network.
And before we saw the command, show IP protocols,
well here I can do a show IPv6 protocols.
And we can look at the three different tables of EIGRP.
Remember we had the neighbors table, the interfaces table
and the topology table.
Let's do a show IPv6 EIGRP neighbors command.
And here we just have one neighbor
and notice, it's known by its link local address.
We know that because it begins with FE80.
And remember our discussion about the hello timer
and the whole time timer,
we see that working and counting down
just as it did with EIGRP for IPv4.
Let's take a look at our interfaces table.
Show IPv6 EIGRP interfaces,
and we've got two interfaces
participating in EIGRP for IPv6.
Notice we've only got a peer off of one of those interfaces.
Gigabit zero slash two connects out to our end users.
There is no neighbor, that's the reason the peer is zero.
And finally, let's take a look at our topology table.
Show IPv6 EIGRP topology.
Here we see the networks that are known to EIGRP for IPv6.
And notice that we know about all of these networks.
That does not guarantee that this network,
from the EIGRP topology table,
will be injected into the router's IPv6 routing table
because the router may know about a better way to get there.
The router may be directly connected.
So for directly connected networks
these routes are not going to be injected
into the IPv6 routing table.
For example, 2000:4::/64, we're connected to that.
So if we look at the routing table, show IPv6 route,
that network shows up with a C, it's directly connected,
we did not learn that via EIGRP.
But the networks that we're not connected to,
as we saw earlier, we did learn those via EIGRP,
as indicated with the D code,
saying this was learned via EIGRP.
And that's a look at how to configure EIGRP for IPv6.
And if we also had IP version addresses on these routers
we could then configure EIGRP for IPv4,
and these two processes could run side by side,
one for IPv4 and one for IPv6.
Now in our next video,
let's take a look at an alternate way of configuring EIGRP.
It's called Named EIGRP.
And there, we're going to be able to create
a single hierarchical structure,
and under that single configuration structure,
we can configure routing support for both IPv4 and IPv6.
I'll see you in that video next.