[AUDIO LOGO]
So now that we have MPLS traffic engineering enabled
on our core, the next step is, of course,
going to be to configure segment routing itself.
We don't have that configured yet so that's
sort of going to be a necessary component for segment routing
traffic engineering.
So let's go ahead and jump in and get segment routing
configured on our devices.
We'll start off with the topology
because I want to show you some stuff that we have already
configured and what we're going to be configuring.
So let's bring up the topology, then
we'll jump into the command line and we'll
get segment routing up and running in our network core.
So again, we are still on MPLS Topology 5.
And what we really want to talk about here
is what's already been configured.
So what I've done is I've already configured
router 7, router 2, router 4, router 6, and router 8.
So what we're going to be working on
is configuring the routers across the top here, router 1.
That way, we get to see an iOS XR device running just IS-IS.
Then we're going to configure router 3
so then we get to see iOS XR with IS-IS and OSPF.
Then we're going to configure router 5.
And of course, this is running iOS XE.
So that should give us a good mix
of being able to see how to configure
these different devices.
So let's go ahead and jump into the command line
and get this configured.
Let's just start on router 1.
So let's start by enabling segment routing for our IGP.
In this case, it's router IS-IS 1.
Of course, we go into the address family
and we say segment routing MPLS.
Commit the changes.
So that takes care of router 1.
Let's go do router 3.
Now remember that router 3 is running two protocols.
So let's start with router IS-IS 1.
Again, we just enable segment routing for MPLS,
then we'll go into router OSPF 1.
Also into our address family, then into area 0.
And then it's the same command segment routing MPLS.
Commit these changes.
We can do some verification as we go here as well.
Let's do a show MPLS label table detail.
We see here that OSPF and IS-IS are both
registered with the SRGB.
And we see down here at the bottom,
entries for both IS-IS labels and OSPF labels
for our adjacency sets.
So so far, this is looking good.
Let's go over to router 5.
This being iOS XE, we have to do segment
routing MPLS globally first.
Then we'll go into router OSPF 1 and enable segment
routing for MPLS here as well.
Exit configuration.
Here let's do a show MPLS forwarding table.
And we can see that we're already
learning adjacency sets.
Notice that we also have prefix SIDs for router 6
and router 8 loopback, which are,
of course, the only routers in the OSPF domain
that are putting a prefix SID into OSPF.
But that means we have to configure
the devices that we just configured
to do prefix SIDs as well.
So let's go ahead and do that here on router 5.
So we go back into segment routing MPLS.
We go into our connected prefix SID map for the address family
IPv4.
And of course, we want to advertise our own loopback.
And we'll just use an index here.
We'll make index 5 since this is router 5.
And we'll exit configuration.
We, of course, need to do this on routers 1 and 3 as well.
So let's go back over to router 1.
So back into router IS-IS 1 for interface
loopback 0 for our address family IPv4 unicast.
And we're going to assign a prefix SID.
And again, we'll just use index.
We'll do index 1.
Commit the changes.
And let's see what we've learned so far from IS-IS.
Let's do a show IS-IS segment routing label table.
What we see here is we're getting
prefix SIDs for ourselves, loopback 0, and routers
2, 4, and 7, which is correct because we haven't configured
router 3 yet.
So let's go ahead and do that.
We'll configure router 3.
Same basic configuration.
We'll just put it into IS-IS on this router.
And this will, of course, be index 3.
We verify our IS-IS segment routing label table.
Now we see that we have prefix SIDs for router 1, 2, 3,
which is, of course, this router, 4,
and 7, which are all the routers in the IS-IS domain.
So again, the domains are still separated,
but within each domain, the prefix SIDs
are being propagated.
Now without the connection between the domains,
we can do a limited amount of testing.
We could go over to router 7.
Here we could do a show MPLS forwarding table.
We see that we are, in fact, learning the labels.
So we could do something, for example, like trace 10.3.3.3,
sourcing it from our loopback.
So we see that's working as expected.
We could also trace router 4.
So we see this is working as desired as well.
So the IS-IS domain appears to be functioning perfectly fine.
Let's jump over to router 8 and take a look at the OSPF domain.
So again, let's do our show MPLS forwarding table.
And notice that we have our adjacency entries
and we have our prefix SIDs to get to routers 5 and 6.
However, notice that all of the outgoing labels are Pop label.
Now this is correct for what we have configured at this point,
but it's not going to do us a lot of good
to trace to router 5 and 6 because we
won't see any labels anyway.
They would just be popped, which means we're not going
to impose one to begin with.
So we won't be able to see labels on this side,
but just based on this output, our label distribution
is working properly in the OSPF domain.
So in this video, we simply enable segment
routing in our network core.
Now a lot of the routers were already
configured but we took a look at routers 1, 3, and 5,
configuring both the routing protocol to support segment
routing as well as configuring our prefix SID for our loopback
interface.
Then, of course, we just did some verification
to make sure that those labels are showing up on all
of the routers appropriately.
But now it's time to join our domains together.
For that, we're going to be using BGP and PCEP.
And that's exactly what we get to configure next.
Until then, I hope this has been informative for you,
and I'd like to thank you for viewing.