All right.
It is time for our troubleshooting lab number two.
And as promised, we're going to have at least one problem
regarding areas, and possibly one or two other issues
that we'll need to resolve.
And here's our topology once again.
And our objectives are to have full connectivity across
the entire network, from R7 via IPv6,
over to R8 gig 0/0 at 2001 DB8 6783 8::8.
And that is it. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And that is it.
So any issues we find along the way that
are preventing that connectivity for whatever reason,
we need to solve it.
So I'm going to go ahead and pause for a few moments,
give you chance to log on to the lab using the virtual link here
at CBT Nuggets, and then walk through
this troubleshooting exercise.
So pause me now.
Work on the lab.
And in a few moments, when you're ready, click on Resume
and we'll do the walk-through.
All right.
Here we go on R7.
Let's go ahead and first verify our routes.
We'll do a show IPv6 route for OSPF learned routes.
WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Network connection fail-- so we have a connection failure
somewhere.
Hmm.
Oh, OK.
So we lost some of our connections here.
That's OK.
It's a troubleshooting lab.
We'll troubleshoot it.
So R4 is having a boatload of messages.
So we'll deal with R4 first and then we'll go back to R7.
So this is saying, OSPF version 3 area mismatch packet
received with incorrect area from, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
received with incorrect area from,
it has a link local address on serial 3/1 area 0.0.0.1.
OK.
So what this is saying right here
is that it's getting hello messages.
And it's indicating that the 0.0.0.1, the area 1
is being used instead of the correct area 2.
And that's coming in on serial 3/1.
So we look at our topology here.
Well, this is pretty convenient, due to the console messages.
So this is R4 saying that R6 is claiming that this
is area 1, when this is area 2. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
is area 1, when this is area 2.
So that's what the console message said.
We'll confirm that.
And then we'll go correct it on R6 if that's the case--
which we've lost connectivity to.
Wow.
OK.
There, back to R6.
Also, if you lose a connection here, you just go to Servers.
And you can open up a new console to R6 if you need to.
Let's go ahead, that is configured in interface config.
So config T interface serial 3/2 IPv6 OSPF process ID 1 area.
And this should be area 2. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And this should be area 2.
So let's see if the madness stops.
Oh, wait a second.
Who's claiming it's-- you know, let's do this.
Let's do show IPv6 OSPF.
And that will tell us exactly who thinks who has what.
So R6 is all area 2.
And let's get to R4 and show--
I just got a little excited--
show IPv6 OSPF.
And sure enough, it thinks that it has an interface in area 1.
So we can do a show IPv6 OSPF interface brief. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So we can do a show IPv6 OSPF interface brief.
So right there, serial 3/1 it's R4's problem.
R4 has an interface, serial 3/1 that
says it's in area 1, when it should be area 2.
So we'll go ahead and correct that.
Config T interface serial 3/1 IPv6 OSPF process ID 1 area 2.
We'll do a show IPv6 OSPF-- oh, there's our neighborship.
So we're good to go.
So we'll do a show IPv6 OSPF. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So we'll do a show IPv6 OSPF.
And there we go.
So area 0, the backbone, and area 2.
OK.
Great.
Wow, we had some weird problems there.
Cool.
And console messages to say, hey, here's what's happening.
And let's go back to R7.
And let's take a look at the routes.
Again, we're trying to get to the 2001 DB8 6783 8 network.
And they're going to be alphabetical here--
alphabetical.
They're going to be numeric here.
So there's the four.
There's the 12.
No 8 network. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
No 8 network.
So let's go back to R6 on the right-hand side
of our topology.
So show IPv6 OSPF neighbor.
Oh, I wasn't expecting that.
So we've got an adjacency with R8, a full adjacency.
So let's do show IPv6 route OSPF.
Why are we not learning about the eight network?
There's the seven network.
The eight would be right here.
All right.
Well, on R8, down here in our topology, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Well, on R8, down here in our topology,
maybe R8 doesn't have this interface gig
0/0 enabled for OSPF.
And that would do it.
We have an adjacency, so we just maybe
don't have OSPF enabled on that gig 0/0.
Let's do a show IPv6 OSPF.
Area 2 has one interface.
OK.
Well, here we go.
There's your problem right there.
So area-- has at least one interface
in area 8, which is not in our topology.
Show IPv6 OSPF interface brief. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Show IPv6 OSPF interface brief.
That'll be good.
There we go.
So gig 0/0 is assigned to area 8.
And as a result, because it breaks the rules,
let's take a look at the rules real quick.
Let's bring up a pen.
And let's also bring up the topology here.
And so what happens at the moment
is R8 thinks that this is area 8.
And nothing wrong with area 8 if it has an area border router.
Because area 8 doesn't have an area border
router connected to it, that's why it's not being advertised. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
router connected to it, that's why it's not being advertised.
So a couple solutions to this would be we could correct that,
and just say, hey, this interface is going to be part
and this network is going to be part of area two, which
it should be.
Or we could configure this interface right here and add it
to the backbone, which would make
R8 an area border router because it has
one interface in the backbone.
That would take a lot of extra lifting.
Or we could do a virtual link.
And a virtual link would also--
from R8 we could do a virtual link to R4
and logically connect it to the backbone WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and logically connect it to the backbone
through its existing area.
So we're going to cover virtual links in a separate skill
that's coming up.
For this troubleshooting lab, let's go ahead and just
take this interface gig 0/0 and put it back into area 2.
And that should make that route then
be propagated throughout the area, area two
so the rest of the routers can see it.
So let's try that.
And let's go back to the CLI and config T interface gig 0/0 IPv6
OSPF process ID 1 area 2. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
OSPF process ID 1 area 2.
And do show IPv6 OSPF interface brief.
That network should now be propagated,
along with its appropriate LSAs, should
be propagated so that the whole rest of the network
can reach it.
So let's go back to--
let's go back to router seven.
And let's do a show IPv6 route and look for the eight network.
There it is right there.
And I'm just going to hit another key
to stop the scrolling.
And let's try to trace to it. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And let's try to trace to it.
So we'll do a trace paste and then we'll
put in the host address of eight for router eight.
And now we have reachability.
OK.
So in this troubleshooting lab, we
had the opportunity to troubleshoot some area related
issues once again.
I think it was either R4 or R6 had the wrong area.
So we corrected that on one of its interfaces.
And also on R8, it had an area eight, which
area eight didn't have an ABR. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
area eight didn't have an ABR.
And so those routes couldn't be propagated because it
broke the rules of OSPF.
So I appreciate you joining me in these labs.
If you haven't yet had a chance to do these hands-on labs
by logging in and actually doing the work, I would encourage it.
It is the best way to reinforce the concepts
and improve your skills in troubleshooting
with IPv6's OSPF version 3.
So thanks for joining me.
I'll see you in the next set of videos
where we will cover some more OSPF related topics.
Until then, I hope this has been informative for you.
And I'd like to thank you for viewing. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And I'd like to thank you for viewing.