[AUDIO LOGO]
Normally, in a service provider core,
we're going to be wanting to run LDP
on all of the same interfaces that we're
running our core routing protocol on,
such as OSPF or ISIS.
Now some of our devices may have a large number of interfaces.
Going and configuring LDP on all of those
interfaces individually when in fact, we really
just want the same interfaces running our routing protocol,
and LDP can get a little bit tedious.
So we have this feature, autoconfiguration,
which allows us to turn this on under the routing protocol,
and then whatever interfaces we enable
for that routing protocol will also be enabled for LDP.
Now like most things that happen automatically,
this is generally a good feature,
but we do want to be aware that you are losing
a small amount of control here.
If you did have interfaces, you maybe
didn't want to be running LDP, in which case,
maybe you still want to configure that device manually.
But let's go ahead and jump in here
and see how we configure autoconfiguration
on our devices.
So there are two ways that we can
use to implement LDP on our devices.
The first is sort of the more traditional way,
which is manually configuring all of the interfaces
to run LDP.
Now, depending on our platform, that
might be under the LDP process, or that might
be under the interface itself.
But nonetheless, it's still a manual process.
Now this does have at least one advantage,
and that is that it does give us precise administrative control
over exactly which interfaces are going to be running LDP.
There is the possibility that we don't necessarily
want to run LDP on all of the interfaces
that are running our IGP.
On a core device, I think that would be pretty unusual,
but it's certainly a possibility,
in which case manually configuring this
might be the way to go.
On the other hand, that can get quite tedious
and even error-prone on devices, particularly
with a lot of interfaces.
Again, human error can come into play here.
We miss an interface, something like that.
Now, one thing to add to this a lot of devices
do support interface range commands,
where we can configure multiple interfaces at the same time.
Some devices do.
Some devices don't.
It really depends on what type of devices
you have in your core whether you can use interface range
commands.
But that could be a way that we could configure
multiple interfaces manually, configuring them
all at the same time.
But for most environments, a better choice
would be to do autoconfiguration.
Now once again, like a lot of the features
we've looked at through this entire section,
this is supported only by OSPF and ISIS.
And that's generally fine because those are generally
the only two protocols that we want
to use under MPLS as our underlay protocol
since they're the only ones that support things like traffic
engineering.
Now the advantage of the autoconfiguration
is, of course, it automatically enables
LDP on the interfaces that are running the protocol.
So once we configure routing protocol,
we're configuring LDP right along with it.
And the other cool thing is this is actually really,
really easy to enable.
So we enable it under the routing process,
and all we have to do on both iOS XR and XE,
we simply say, mpls ldp auto-config.
Now in OSPF specifically, if you want,
you can specify an area by simply adding
area_id to the end of this same command here.
So if, for some reason, you only want
to run LDP in a particular area, that's
also an option with autoconfiguration.
In this video, we took a look at a way
to automate enabling LDP on our interfaces
right along with our routing protocol.
This, of course, is called autoconfiguration,
as we just saw.
And it's only supported with OSPF and ISIS, which, again,
is generally fine because those are usually the only routing
protocols that we want in the underlay anyway.
Keep in mind, though, if you do need
more administrative control than this,
you can always just revert to doing it manually.
So that covers everything that we
need to discuss in this skill.
That leaves us only with a review in the form of a quiz.
And that's exactly what we're going to do next.
Until then, I hope this has been informative for you,
and I'd like to thank you for viewing.