I'm having a lot of fun in these troubleshooting labs.
And this is the spoiler alert, the walkthrough,
for EIGRP troubleshooting for IPv6.
[MUSIC PLAYING]
And here's our objective, from R4,
focused on IPv6 in this walkthrough,
we want to take the optimal path through the network, which
is this path, from R4 through the gig 0/0 interface on R7.
So if you've tried or worked on this lab
and you're ready for the walkthrough
to reinforce what you've learned, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
to reinforce what you've learned,
this is our opportunity.
Let's go to the CLI.
All right.
So we're going to start out by verifying the problem,
and that is the IPv6 connectivity.
So I'm going to go to R7.
Show ipv6 interface brief.
We'll grab that interface on gig 0/0, which is right here.
2001 db8 6783, 7, 7.
And we'll go to R4.
And we will do a ping to that address.
No.
No valid route.
So sad.
All right, we'll do a show ip route-- WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
All right, we'll do a show ip route--
excuse me, for IPv6, show ipv6 route.
All right, so we've got a lot of EIGRP learned rules.
So I'm going to do a show ipv6 eigrp neighbors.
OK, so we have neighborships off of gig 2/0, 3/1, and also 4/1.
Look at our topology.
That's good.
We have three neighbors.
That looks fantastic.
So why are we not using the optimal path? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So why are we not using the optimal path?
Let's go ahead and take a look closer at that.
Wait a minute. we don't even have a route for that network.
And so I scroll just a little bit.
That's the 7 network.
So here's the 6 network.
Here's the 8 network.
Yeah, there's no 7 network in there.
All right, so we've got neighborships.
R4 appears to have neighborships.
So let's do a--
hmm.
Let's move further in the network.
Let's move over closer to R7.
Let's go to R3.
Kind of divide and conquer.
Move one step closer and see if R3 can access that WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Move one step closer and see if R3 can access that
or reach that network.
So let's do that.
So here on R3, we'll do a show ipv6 route.
And the 7 network is not in this routing table either.
Let's go down to R5 then.
Let's do a show ipv6 route.
Oh, and this guy's got-- this guy
has no EIGRP learned routes.
And why is that? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And why is that?
Show ipv6 eigrp interface.
OK, he's enabled.
And he has one peer off of gig 1/0.
That's going down to R7.
Huh.
Let's do a show--
mmm.
That's weird.
Show ipv6 eigrp neighbors detail.
Oh, right here.
Receive only peer, advertising no routes. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Receive only peer, advertising no routes.
So this is effectively using the stub command
and with the option of receive only.
So we are not--
we're neighboring.
We know about R7.
But we're not learning any routes from him.
So if we want to reach that network of the gig 0/0,
we are going to need to tell R7 not to be a stub
and not to not advertise routes.
Or be a stub, but at least advertise connected.
Let's go to R7.
And let's do a show ipv6 protocols. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And let's do a show ipv6 protocols.
Let's do a show run section router.
And let's take a look at what they've got there.
And survey says-- so for the address family ipv6 unicast
autonomous system 6--
oh, maybe I cut it off too soon.
Hold on one second.
Let me just do it again.
And let me hit the spacebar this time, because I cut off
the part that I needed to see.
There it is, right there. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
There it is, right there.
EIGRP stub receive only.
So he's not advertising anything, as far
as information, as far as networks.
Let's do a config t.
And we'll go into router eigrp for that named EIGRP
configuration.
And then we'll go into the address family.
I'm just going to double click and then right
click to paste it in for IPv6.
And then it's right here.
It's not in the topology base.
It's not in the AF interface.
So I'm just going to go--
I'm going to take off the stub.
Say no. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Say no.
And then I'll just go ahead and tell it no longer to be a stub.
All right.
And OK, so we got a new adjacency.
That's much better.
So if we go to our R5 and we do a show ipv6 route,
we're looking for the 7 network, and there it is right there.
So let's just verify that we can ping.
And I'll go back to R7.
I'm just going to copy it.
Less typos that way.
Show ipv6 interface brief. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Show ipv6 interface brief.
We're looking for gig 0/0.
And there it is.
We'll go back to R5, make sure we can ping it.
And we're going to verify the path as well,
although that's where we learned this, so I think we're good.
Yep, wants to R7.
OK, so let's go back to R4 and see
if R4 can reach that as well.
Traceroute to that same address.
Oh, well.
Well, this is improvement.
So we have R6, R8, R7, based on that last number WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So we have R6, R8, R7, based on that last number
of the IPv6 address, is the path.
Not the optimal path, though.
So it's going from R4, down to R6, down to R8.
And we're at R7.
We want to take the northbound path.
So we already verified on R4--
let me get my pen out here.
We already verified on R4 that we
have neighbors with R2 and R3.
Let's go over back to R3 and just verify that R3 in reach.
And then we'll just keep working our way back
until we find the problem about who's breaking
the chain of making it work. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
the chain of making it work.
Chain is not a Freudian slip regarding a key-chain that
might be wrong, although that authentication could
be messed up too.
We'll take a look.
All right.
So let's go to R3.
So away we go to R3.
And-- all right, R3.
Show-- just up arrow key.
Show ipv6 route.
Oh.
OK, we actually have IPv6.
And I see the 7 network right there.
Let's go ahead and do a trace.
And I still have it in my buffer.
Oh, I highlighted something. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Oh, I highlighted something.
So we'll go back to R7, grab that interface IP
address again.
Go back to R3.
And then traceroute to it.
Oh, my gosh.
It's going wrong.
That's R3 going to 1 to 2 to 4 to 6 to 8 to 7.
They're going the wrong way.
1, 2, 4, 6, 8, 7.
Let's take a look at the topology.
Got to be something like this.
It's going 1, 2, 4--
what, 6 wasn't in there? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
what, 6 wasn't in there?
Hold on a second.
I need to make sure I have this right.
1, 2, 4, 6 8, 7.
My bad.
OK.
And then there's no tunnels in this topology.
So I was surprised.
So it's going this direction.
1, 2, 4, 6, 8, 7.
That way.
I can't think of a much worse--
I mean, any port in a storm, right?
But a path is a path.
But it's terrible. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
But it's terrible.
Serial links here and here.
So it would appear that if R3 is going this way--
let's just take a look at R3 and figure out
why it doesn't have a route down to R5.
So we'll check neighborships.
We'll check all the details, authentication.
And we'll get that neighborship working, because that'll
be the optimal path.
So back to R3 we go.
And I literally cannot remember the problems I put into this
lab.
So it's good for me too. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So it's good for me too.
Having a good time with you in this troubleshooting.
So R3, do a show ipv6 eigrp neighbors.
And 4/0, 1/0, 3/2.
But not 4/1.
OK, so we don't have a neighborship off of 4/1
down to R5.
Let's go back.
And let's see if we have EIGRP enabled for that IPv6.
So ipv6 eigrp interface.
WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And Enter.
So that is interface 4/1, and it is not enabled.
I don't see it enabled.
All right, so let's do a show ipv6 protocols.
Our K values are here.
We have the variance here.
Interfaces.
Yeah, that interface isn't included. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Yeah, that interface isn't included.
Let's take a look.
Let's take a look at the routing config.
So show run.
And we'll do a section router.
All right, here we go.
Let's see what mysteries are waiting here.
Survey says-- address family IPv6.
There's authentication.
Oh, right here.
And check it out.
Because we have af interface FE 4/1 underneath the address
family, and we've specified shutdown. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
family, and we've specified shutdown.
That's why we're not participating with EIGRP
on that interface.
So the difference between passive interface and shutdown
is the passive interface includes
the network in the EIGRP.
Just won't become a neighbor.
Shutdown says, nope, nope, nope, nope, nope.
No EIGRP whatsoever for IPv6 on that interface.
All right, so let's fix that by bringing it-- or telling it
not to be shut down.
So we'll go to configuration mode.
And that's going to scroll up a little bit.
And grab the-- so I'm just going to grab this. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And grab the-- so I'm just going to grab this.
Just going to double click on it and paste it in.
And then we'll double click on the IPv6 address family,
paste it in.
And then we'll go into AF interface 4/1.
And then we'll do a no shut.
Yeah, and there's our neighborship.
There's your problem right there.
OK.
So let's go back to R4 and do a test again.
So we don't want to go 6, 8, 7.
We want to go--
let's just make sure where we want to go. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
let's just make sure where we want to go.
We want to go 2, 1, 3, 5, 7.
2, 1, 3, 5, 7.
That order.
So let's give it a shot.
2, 1, 3, 5, 7.
So in this hands-on practice for troubleshooting
with EIGRP for both IPv4 and IPv6,
there is one major lab that had all the problems baked into it,
both for IPv4 and for IPv6.
And in the previous video, we walked through the solution
for IPv4.
And this time, we focused on IPv6.
And as we troubleshoot with the EIGRP,
we'll get better and better. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
we'll get better and better.
And let me share with you a couple of additional commands
that we can put in our Batman utility belt
to help us as we troubleshoot EIGRP for either IPv4 or IPv6.
One of my favorite commands would
be show ipv6 eigrp topology.
And we've talked about that previously,
both for IPv4 and IPv6, looking at the successor routes,
the feasible successors.
And that's good for both IPv4 and IPv6.
For IPv4, we just say IP.
And that will show us the topology table for IP. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And that will show us the topology table for IP.
There is also an option for summary.
And that can show us how many routes that we've learned.
Also if we are waiting on replies coming back,
like we did a query and we're waiting for a response,
that can show up here.
Another fun command is show ip eigrp topology.
Then we can follow it up with this one, 0 successors.
And this is really cool.
It's showing us here that for this network, 10.2.46.4,
the 32-bit route, it knows about it.
It knows about individuals or neighbors WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
It knows about individuals or neighbors
that have advertised that route to it, R2, R3, and R6.
But none of these routes got into the routing table.
And that's because there's some better route.
So we can take a look at what that better route is
if we do a show ip route.
And that's going to go ahead and put this bad boy in.
Press Enter.
And here, it's showing us who won.
It's a directly connected network with a distance of 0.
A static route by default would have an AD of 1.
And a directly connected network would have an AD of 0. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And a directly connected network would have an AD of 0.
And that beats out the EIGRP's 90.
And while I have you, another command that's kind of helpful
too is a show ip eigrp event.
And all these commands have similar commands
for IPv6 x flavor as well.
So show ip eigrp events is going to show you
the detail behind the scenes of what's
going on in the world of EIGRP and its dual algorithm it's
using to calculate the best routes.
Another fun one to show, ip eigrp and traffic. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Another fun one to show, ip eigrp and traffic.
And that's another great one too.
So as far as hellos sent and received,
updates sent and received, queries sent and received,
replies sent and received.
So the hellos and also the acknowledgments
are not sent as reliable.
They're not sent with a sequence number,
and they're not waiting for a follow-up.
But updates, queries, and replies,
those are all acknowledged.
So if we send out a query, we'll send it with a sequence number.
And then we're expecting a response back
from the neighbor, either good or bad, regarding that request. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
from the neighbor, either good or bad, regarding that request.
And down here, we have stuck in active queries sent/received
and stuck in active replies sent and received.
And having zeros for stuck in active is perfect.
We do not want to be stuck actively in a query
and waiting on a response for a long period of time
regarding a route that went missing.
Now, if we did have some active routes
and we thought, wow, we've got stuck in actives,
we can do a show ip eigrp topology.
And there's an option for active.
So we can say active there.
And it will show us any of the routes
that it's currently gone active for that it's looking for. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
that it's currently gone active for that it's looking for.
So if we go to interface loopback 0, and before we
shut it down, we do the command do
show ip eigrp topology active.
And then we'll go ahead and do a shut and hit the up arrow key
a couple of times.
And you have to do it really quick because it's
going to go active, then it's going to get the response,
and no longer will it be active.
So right here, this output of show ip eigrp topology active
indicates the current route that it just went active for.
And if we did that up arrow key again,
it's no longer active because it got WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
it's no longer active because it got
the responses back it needed.
And one more that's a fun one is we
could ping the EIGRP multicast address.
So R4, if we look at our topology,
it should have three neighbors--
R2, R3, and R6.
So if we did a ping to the multicast address of 224.0.0.10
and pressed Enter, we should get responses
from each of our peers.
And there's 3, R2, and R6, which is awesome.
And if we did a ping-- let's do a show ipv6 interface. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And if we did a ping-- let's do a show ipv6 interface.
So there is the multicast address for IPv6.
So if we did a ping to that--
and I'll just paste it in-- that's
the multicast address for IPv6 EIGRP.
And press Enter.
And because it's using link local addresses
like I specified in the interface, let's pick on--
let's pick on FA 4/1.
And it didn't like the space.
All right, Fast Ethernet at 4/1.
All right.
And now we have the replies coming in.
Those would be the link local address
of whoever is off that circuit.
That would be R3. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
That would be R3.
We can verify that real quick too.
We'll do a R3 and do a show ipv6 interface for.
And that interface is--
that is going to be fa 4/0.
Fa 4/0.
And there it is.
And again, 6470 for the link local address.
And if you go back here to R4, that
is indeed the link local address that was responding back to us.
So I would encourage you to play around with troubleshooting
labs and get better and better.
And the more you practice, the better you'll get at it.
So I appreciate you joining me in this set of videos WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So I appreciate you joining me in this set of videos
on troubleshooting EIGRP, both IPv4 and IPv6.
And I'll see you in the next set of videos.
Meanwhile, I hope this has been informative for you.
And I'd like to thank you for viewing.