In the previous video, we looked at how
BFD bi-directional forwarding detection can improve
the convergence time for OSPF.
And even though each EIGRP is pretty fast,
it can also help the conversion time for EIGRP.
And in this video, that's what I'd like to walk you through.
Let's take a look at our topology.
Here is our topology.
Once again, all the interfaces are back up and running.
And the interface here is gig 0/2 on R2,
and 0/0 on the switch, and 0/0. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and 0/0 on the switch, and 0/0.
And what I'd like to do is implement EIGRP
on this network on top of OSPF.
I'm just going to leave it there,
because OSPF has a worse administrative distance
than internal EIGRP routes.
So that'll be fine.
And then, what we get to do is tell EIGRP
that we want it to pay attention to the BFD.
And that way we can improve the conversions time.
So even though EIGRP is pretty quick,
the hello time is every five seconds,
and the dead interval is like 15 seconds.
We can get that time a lot shorter,
as well, by just using it alongside of BFD. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
as well, by just using it alongside of BFD.
So before we begin, let's go to R1,
and let's do it trace route to 4, 4, 4, 4.
We want to verify that we're going to R2 and then R4,
and not some other path.
Great.
And currently, those are courtesy of OSPF,
but we're going to fix that.
So here are the commands.
So the slow timers-- once again, I'm
doing because I'm in a lab environment with the Cisco
modeling labs, so I don't blow up the gear.
And then on each interface that could potentially
be involved with BFD, I'm setting
the BFD interval of send 850, the minimum receive of 950. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
the BFD interval of send 850, the minimum receive of 950.
And what they're going to do is, they're
going to go into negotiate.
So which one ever has the worst speed, or the lowest
speed as far as--
whichever one has the biggest interval-- that's the one
they're going to use.
And the multiplier of 3 says that after 3--
that's where I'm going to go ahead and consider them dead.
So we're doing that on each interface.
And I'm going into router EIGRP autonomous system 1.
And we're going to specify network everything,
and then say BFD all dash interfaces.
And that syntax is just like it was with OSPF,
as far as the BFD all interfaces command. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
as far as the BFD all interfaces command.
So we'll take that.
And let's go ahead and put that--
because we're going to cause a failure between R2 and R4,
that's the only place I'm going to go ahead and put it.
So R2, right click, paste.
And R4, right click, and paste.
And then to verify this, before we go, let's go to R2.
And let's also do a show BFD neighbors detail. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And let's also do a show BFD neighbors detail.
And regarding the interface, that
is gig 0/2, which is the one going up
to the neighbor 10.24.0.4 right here.
Notice here that it has OSPF that
was from the previous demo.
And now it also has associated with it, EIGRP,
which means EIGRP is paying attention to that.
So let's make sure we have a clean path to the network.
Do they put the command everywhere?
Even though I'm only going to use BFD on those two routers,
I also need EIGRP across the network, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
I also need EIGRP across the network,
so everything's going to load together.
So let me go ahead and do that for the entire device--
for the entire topology.
I'll take all of them, and just give them
all that configuration.
There's R1.
We did R2.
We did R4.
Go to R5, and paste, and R3, and paste, and great.
So let's just do a quick check on R2.
And we'll do a show BFD neighbors detail. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And we'll do a show BFD neighbors detail.
And there's more than one word that-- more than one option
because of d.
So details.
And if we look at our neighbors--
they're all going to be associated with OSPF and EIGRP,
including our neighborship that we have
with a 10.24.0.4, which is R4.
Great.
So we're supporting EIGRP.
Now, on our 1, if we do a ping--
do 4, 4, 4, 4 and repeat 1,000 times. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
do 4, 4, 4, 4 and repeat 1,000 times.
And before I press enter, let me go to R2--
the switch and shut down the interface between itself
and R4.
And we'll do a shutdown.
Let's go ahead back to R1.
And we'll do the ping.
And we'll see how long it takes to come up.
So by itself, well, EIGRP is pretty fast.
It could've been EIGRP just being rock solid fast,
too, because that didn't take long for it to converge.
So the challenge here is that if we
have R4 going to a switch and R2 going to a switch, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
have R4 going to a switch and R2 going to a switch,
if one side goes down, the other side still has link.
And as a result there's--
you have to rely on the timers built in the routing protocol,
or them to detect it.
Oh, we're having a problem.
And the BFD is a great solution for that.
So I think on this one, because my timers
are pretty big for BFD--
I think EIGRP just converged on its own.
But if we did this on R2, and we did a show BFD neighbors--
it's going to show us that our neighborship to R4 is down. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
it's going to show us that our neighborship to R4 is down.
And that's because there is no longer
the responses to the messages going back and forth.
And EIGRP and OSPF are paying attention to that.
So in preparation for the next demo,
let me go back to the switch and let's do a no shutdown.
And once you do that, let's go back to R2.
And we'll use the same command here, show BFD neighbors.
And we'll make sure the neighborship with R4
comes back.
Now on the layer 2 switch, there could be a little latency
because of spanning tree.
Brought the port back up.
So if it's using spanning tree, even rapid WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So if it's using spanning tree, even rapid
spanning tree without port fast--
it could be a few moments.
So we'll wait for it.
Come on BFD neighborship.
Come on.
We need a neighborship with 10.24.0.4.
There it is.
Oh, that was-- oh, it's like a party.
OSPF, EIGRP, BFD-- they all came up.
So we do a show BFD neighbors.
That's going to show our neighborship.
So in the next video-- WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So in the next video--
let me go ahead and queue this up.
In the next video, we're going to do BFD with BGP.
And that way with a BGP neighborship,
we can also have a BGP neighborship
go belly up or bail out if the BFD session between them
has failed.
So we'll do that in the next video.
Meanwhile, I hope this has been informative for you.
And I'd like to thank you for viewing.