I've always felt that the more comfortable
I am with the topology and where things are,
the better we're going to be at troubleshooting.
And so in this video and lab, I'd
like to present you a working topology
so you can get comfortable with where stuff
is, some of the common commands we'd use, and then
be ready for the next video to get hands on troubleshooting.
[MUSIC PLAYING]
So here's the topology that you and I get to practice and play
with for IPv4's flavor of OSPF.
And we've got eight routers here. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And we've got eight routers here.
This is area 0 over here.
And over here on the left we have area 1.
And over here we have area 2.
For this immediate set of labs, we're
not going to be using these two links here.
They're not enabled for OSPF, nor do they need to be.
And as far as the networks go for IPv4, I'm using this model.
So it's 10, the 10 network.
And then area.
So all the networks up here are going
to be in that second octet.
They're going to be a 0.
And then we have RR, which is router to router.
So from R1 to R2, that'd be 12. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So from R1 to R2, that'd be 12.
From R3 to R4 it'd be 34.
From 3 to 5, 35 and so forth.
And then the last octet for the IPv4 address,
we're going to use the router number.
So R1 will always end in dot 1.
R 6 will end in dot 6.
And that way it'll be easy to remember where things are.
One exception to this plan here is down here off of gig 00
on R8 I have the 192.168.1 network with the 24-bit mask,
but it is dot 8 here as far as the last octet on that device.
And then for this network here, this is network 1. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then for this network here, this is network 1.
That's the third octet there.
And off R7 would be that third octet.
And then they have some PCs.
I've got PC 1 here and PC 7.
They're in the lab environment.
And also PC 8 over here if you want
to use those for connectivity tests or for anything else.
So this is the topology.
When you get prepared to work on the labs,
I would recommend that if you have two screens, that's great.
My preference.
And that way you can have one screen with the topology
and the other screen for the lab.
Or print it out. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Or print it out.
Or use a tablet and log in one time with the tablet
so you can see it.
That's very, very helpful just to remind ourselves
of where we are at.
So let me give you a tour of the command line interface
in working with these devices.
All right.
And let's start off on R3.
It's an area border router.
It's easy to verify.
[INAUDIBLE] doing a show IP OSPF.
And press Enter.
There's a lot of output here.
But some of the things it'll show you is its role.
So it is an area border router.
And why is that?
If we scroll down to the bottom, it's
connected to the backbone area and one other area. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
connected to the backbone area and one other area.
And as far as that other area, it
can show us details about that area.
And regarding non backbone areas that it's connected to,
this ABR can give us information about how it's configured,
regarding authentication for that area and what type of area
it is.
Is it a stub or a not so stubby area?
If we have an ASBR, an Autonomous System Boundary
Router, we're going to have external routes
in the routing table.
So let's do a show IP route for OSPF learned routes.
I've got some inter area routes. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
I've got some inter area routes.
And here we go.
Look at these externals right here.
We've got five of them.
So those five routes are all LSA type 5s.
And there happens to be five.
But those are LSA type 5.
So if you do a show IP OSPF database,
we're going to see those external LSAs here on R3,
and they'll show up as an LSA type 5
if we do a show IP OSPF database.
And we'll do a question mark.
And let's go ahead and put in external.
That'll just show us those external LSAs.
So here we have the LSAs for the external networks of 10.0.11.0. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So here we have the LSAs for the external networks of 10.0.11.0.
And if we scroll down, there's 10.0.11.8.
And then we have 10.0.11.16.
Also shows who the advertising router is, which is R1.
If we went up to R1 and did a show IP OSPF and pressed Enter,
it's going to show us that it is an autonomous system boundary
router.
And it's redistributing external routes from static.
And that's why it's an ASBR.
And if we continue the output of this--
I'll do the up arrow key and we'll do it again--
we can see that this guy only has interfaces in the backbone, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
we can see that this guy only has interfaces in the backbone,
meaning that he is not an ABR.
He is an internal router in the backbone area.
And it looks like he has four interfaces, one being
a loopback in that area 0.
So I invite you, if you're logged on to the CBT Nuggets
website from a PC, click on that link for the virtual lab.
Become familiar with this topology,
because in the very next lab we are
going to start with some troubleshooting regarding
area types inside of OSPF.
And, as promised, I'll also inject
a few other little tidbits so that there WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
a few other little tidbits so that there
is going to be some additional work
to do to solve the troubleshooting
challenge that's coming up in the next video lab.
So I'll see you there in just a moment.
Meanwhile, I hope this has been informative for you.
And I'd like to thank you for viewing.