- [Instructor] Now that we understand
network address translation,
let's run out and do a lab.
In this case I'm willing to use the center router,
which was my corp router,
notice I have serial zero one one, my inside serial,
zero zero one on my outside.
In reality you'd have a LAN on the inside of course,
but in this case it's going to work great for our laps.
I also have a new router, on the left, which I've named PC,
and another router on the right, on the outisde,
that I've named Internet.
Let's run out to the corp router and configure, static NAT.
On the corp router, I'm just gonna come in here
and my interface is already configured.
So when you're doing NAT of any type
make sure your network's up and running,
your IPs are good in your routing protocol,
and you can ping from end to end.
So the first thing I'm gonna do is go into my interface's,
interface S zero, now,
this is one of the objectives for Cisco CCENT on NAT,
is what's the first thing you do in configuring NAT.
This isn't necessarily the first thing, but it can be.
Is I'm gonna do the, mark the interfaces,
and zero one one is inside.
And so marking your interfaces as from Cisco
is the first thing that you do for NAT, is what they said.
So once, I'm gonna mark these, zero one one,
zero one, is my outside.
And I'm just gonna, up arrow,
and then change that to outside.
So I've marked my inside and outside,
again you don't have to do these first, all right?
I just did them first.
Now, I want to go ahead and allow
the 10.1.1.2 host to the internet.
All right, so, I'm gonna say,
it's pretty simple guys, it's global config.
Now, the thing about static NAT, as you know,
it's just one line per host.
IP NAT inside, so from the source that's inside,
we're going to do static NAT, one to one translations,
10.1.1.2 can use 209.165.201.5.
So I'm going to go ahead and add that in there.
That's pretty much it.
So it's a one to one translation,
if you had 50 users, you'd have to do this 50 times,
so we typically won't do this.
You'd have to have 50 addresses.
And I'm going to log in.
I just named my router, Internet, right?
209.165.201.2 is the actual address.
But I gave myself an address of 5.
Again, you can't just make up these addresses.
So let's go back to the corp router for a minute.
The corp router.
Show IP NAT translations.
And we can see our translation down here at the bottom.
We can see there was ICMP, TCP,
these protocols were used when I used ping and telnet,
but they are not used to reference my session.
This right here is my inside local,
10.1.1.2, this was my address before translation.
My translated address is 209.165.201.5,
that this host, Bob, or whoever it is,
is using to get onto the internet.
Okay so that's how you easily can configure static NAT,
and then verify with the show IP NAT translations command.