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- So, at this point, we have EIGRP up and functional.
We have end to end IP connectivity.
But the lab also said that between two routers,
we had to include EIGRP authentication.
So in this particular video,
that is where we're gonna add in that particular element.
So, remember, as far as the lab was concerned,
EIGRP authentication's supposed to take place
between Router One, actually, they gave us freedom, alright,
you could have it happen between any two routers
in your network.
I'm just choosing to have it happen
between Router One and Router Three.
If you wanna chose a different pair of routers,
that's perfectly fine.
Okay, so let's go ahead and get it working
between these two routers.
So with EIGRP authentication,
it's basically a two step process.
Number one, we have to configure something
called a key-chain at the global configuration level.
And that key chain is what's gonna contain our password,
otherwise known as a key-string.
Then, we have to go to the interface level.
And on the interface level, we have to tell it:
"hey, when you're speaking EIGRP,
I want you to implement authentication
and I want you to refer back to this key-chain
and you'll find your password over there."
So let's go ahead and do that.
Let's create the key-chain first on Router One.
Key-chain, and I'll just call it INE.
And here we'll say key 1.
We're just gonna have one password in this particular case.
And key-string will also be INE.
Save our config.
Now, before I actually do this,
let's back up here for a second.
Let's close this out.
Let's shut down all of our routers.
And let's create a snapshot of where we are right now,
before we add in our authentication.
So, we've already created one snapshot,
which was called IP addresses only.
Now, let's create another one called EIGRP basic
and we will remember that's the configuration
where EIGRP was working but we hadn't modified it yet
by adding authentication or anything else like that.
And once again, remember that in order to create a snapshot
or restore to a previous snapshot,
all of your IOS devices have to be in the powered off state.
Now let's go ahead and turn it back on.
Let's go back to Router One and take up where we left off.
Now you should still have that key chain in there
because I did save it with the right memory command.
Let's just verify it.
Yes, he does, okay.
So now let's go on to his interface, int fast 0/0.
Now we're gonna say ip authentication
and then we'll say mode eigrp 100 md5.
So we're saying for EIGRP autonomous system100
on this interface, use md5 authentication.
Then, we have to say
ip authentication key-chain eigrp 100 INE.
Basically saying, refer back to the key chain called INE
and you'll find your password, or passwords, there.
Let's save this.
Let's do a sho run.
And now, you probably won't have this ability
in any kind of simulations or anything that you do
on your CCNA exam, you probably won't have the ability
to do this.
But, what I'm just gonna do, is I'm going
to copy and paste the relevant information over
to the other router.
So let's go down to my key-chain here.
Here we are.
Copy and paste this in here.
And then let's go down to the interface.
FastEthernet0/0 and let's just copy that.
Strip out that IP address,
though because that will not be relevant for Router Three.
And at the end of this, we'll just say, end.
Okay, so let's go ahead and save Router One.
And now, let's get into Router Three.
Okay and then let's just paste in what we just did
on Router One, all of the relevant stuff matches exactly.
Right click.
And the neighbor relationship comes up so how do we know
that authentication's working?
Well, there's several ways.
Sho ip eigrp neighbor, if authentication had failed,
we would not have a neighbor on that interface.
Also, sho ip route eigrp, if authentication had failed,
we would not have learned about any eigrp routes
on that interface.
So it's sort of by inference that we can assume
that authentication's working because if it wasn't working,
none of this other stuff would be working either.
So we'll save our configuration here.
Bring this down.
Turn off all of our routers
and let's create another snapshot.
And we'll call this one EIGRP-authentication.
And then, close.
And that concludes this section of the video.
So now we've got one more task to do in the next video,
the last one of this particular lab.
We're gonna number one, verify what path is being used
between Router One and Router Four to ping their loopbacks,
which is most likely that bottom path,
the FastEthernet path.
And then we're gonna manipulate EIGRP so that ultimately,
when they ping their loopbacks, they end up going
across the slower speed length on the top.
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