- In this video I want to introduce you to the concept
of connecting your GNS3 simulated network
to an actual live external network
or a live external device.
It' doesn't have to be a network.
Maybe you want to take your GNS3 topology
and you want to practice AAA,
you want to practice radius
but you need a radius server to do that.
Maybe you've actually got another laptop
or a server sitting right on your desk
that actually has a radius server application running in it
and you want to connect that
to your simulated topology in GNS3.
Or more likely, if you're like a CCNA or CCNP student,
you probably want to practice
some of those switching commands
that are not available in the etherswitch module
or in the built in ethernet switch node within GNS3.
And so you want to once again connect your virtual topology
to a real, physical switch.
So here I'm gonna start the process
of explaining how that's done.
We're gonna look at it from the perspective of
connecting my GNS3 topology into a switch port
on a real external switch
and that switch port is configured as an access port.
So before we actually get into
the actual mechanics of how this works,
let's go ahead and take a look first of at
what I'm actually going to be doing.
So this right here represents my actual layout.
My topology here.
So this is my laptop
and this right here is an actual physical switch
I have sitting next to me.
And I've got that physical switch turned on right now
and I have a real ethernet cable
connecting one of the ports of that switch
into the actual ethernet NIC card of my laptop.
So that's how I'm doing this.
With GNS3 you actually could even use your
WiFi NIC card and connect it via WiFi.
Now certainly you're not gonna be able to do that
to connect to a switch,
but if you want to connect to a physical device
like a switch or a server,
key point is, you take that physical device,
whatever it is, in this case a switch,
connect it via a real physical ethernet cable
into the NIC card of whatever laptop or device it is
where you're actually running GNS3.
Now here within GNS3, I've got GNS3 up and running
and I've got my virtual topology built.
And here's how we're gonna connect this all together.
I'm going to use one of the built in nodes
within GNS3 called the Cloud node.
Now let me preface this by saying
I could also select the Host node.
Cloud node, Host node,
they both do the exactly same thing
and in just a moment I'll talk about
why you might want to use one over the other.
And so once I have the Cloud node in there,
I'm gonna configure that Cloud node
so that it recognizes that it should connect externally
to my actual NIC card.
So I'm gonna configure the Cloud node
and also if you were using the Host node, same thing.
Make it realize it'll be a configuration
that's connecting to your LAN adapter, your NIC card.
And then after that's done,
using just the regular Add a Link tool that's within GNS3,
I'm just gonna add a link
between the fast ethernet port of my router
into the Cloud.
And so by this Cloud node here,
this is gonna be the thing that's actually gonna
connect my simulated environment
to my real physical hardware on the outside.
So how do we go ahead and do that?
So like I said, I've already got the physical piece done.
I've got the switch powered on.
I've got the switch physically cabled
into the ethernet port on the back of my laptop.
And I've got the switch, you know, running.
Right now I've changed the host name to Keith-Switch
just to make it unique.
So at that point I'm gonna go into GNS3
and just to make this super simple
I'm just gonna use a single router.
I don't need to have a real big topology
in order to demonstrate the fundamental concept here.
And so now I'm gonna click on right here,
this part here which is the Browse End Devices,
and you'll see I've got Cloud in here.
So just drag and drop that into your topology.
And now right click on Cloud.
There's no command line interface for this.
Just like how the ethernet switch didn't have a command line
and others, the frame relay switch.
So you're just gonna use the Configure button here.
And now here
under Ethernet you've got various options.
So what this is saying is,
OK, how is the Cloud node gonna connect
to the outside world?
And if you select this drop down box
I could have it connect to the outside world
via my WiFi card.
In some scenarios it might research online
they recommend configuring a loop back adapter
and then connecting your Cloud to that.
But in my particular case,
I'm just gonna have my cloud connect
to my Local Area Connection.
This is my LAN adapter.
And then I'll click Add.
And then at that point
I just click Apply
and then OK.
So now my Cloud knows how it's supposed to connect
external to my laptop.
In other words, what physical NIC card
on my lap top should it be connected to.
So now it's simply a matter of
using the Add a Link tool.
Go to my router, select his fast ethernet link.
You're gonna have to do this via ethernet.
You can't select a serial interface or anything.
And connect it to the Local Area Connection right here
that you see within the Cloud.
Okay, deselect that.
Now at this point, before I go any further,
I know that this Cloud really represents
a switch that I'm connected to.
So I can actually right click on the Cloud
and click right here where it says Change Symbol.
Now I'm gonna go ahead and scroll down
and I know that's actually connected to a multilayer switch.
I've got a 3750 sitting next to me right here.
So I'll actually change the icon to be multilayer_switch.
Don't have to do this,
it just makes it so that
when I'm looking at it in the topology,
it looks a little bit better.
So I actually know what I'm looking at right here.
Now you can't change the name,
it still has to represent as Cloud.
Right now it's saying Cloud 2
because I already created a Cloud to test this out
before I did the video.
But if this is your first Cloud,
it'll probably say Cloud 1.
Alright, so now I'm done with that.
Go ahead and go in my router and start it.
Now one thing you'll notice,
and the switch might talk about this.
Now my particular case it's not,
but when I did this the first time,
you can see I was getting
duplex mismatch messages.
And that's because by default
the routers interface that's connecting into the Cloud
is running half-duplex
and the switch was saying, hey I'm confused.
I'm running full-duplex
the thing I'm connected to is half-duplex
but we can fix that real easily.
So let's just double click in the router
and now we're in that router here.
So we just go into the routers interface.
And whenever you change things at
the physical or the data link layer,
I always recommend that you shut down the interface first.
You can just have unpredictable results if you try to change
physical or data link layered characteristics
of an interface while that interface
is actually up and running.
So I'm gonna shut it down.
And now I'm gonna changed the duplex to full.
Then I'll do a no shut.
Okay.
And now how do I know it's actually connected?
Well there's a couple of ways.
One way you can do,
is because my switch is doing CDP
I can just do show cdp neighbor
on my virtual or my emulated router.
And you can see right here,
it's connected to Keith-Switch.
Another way I can tell this,
is on my actual switch.
Now I connected it physically,
let's go back to my drawing right here.
I connected it physically to port 0/2.
That's the port that I'm actually
connected to on the switch.
And on the switch
sh run int fast 0/2
You can see I've just simply configured it as an access port
and it's defaulting to vlan1.
And then what I also did,
is under my vlan1, under my switch virtual interface,
I gave an ip address.
And then on my router here.
Nope, still getting a duplex mismatch.
Let's take a look at our interface.
Fast ethernet 0/0.
This might just be an old message.
Let's take a look here,
sh int fast 0/2
and right now this guy is full-duplex.
So we should have parity here.
We should have full-duplex on both sides.
I'm gonna ignore that message for the moment.
So on the router side you can see,
let's go ahead and configure an ip address
on that router's interface.
This is just gonna give further proof
that I am really connected to that external device.
Ip add 1.1.1.2
because my switch was 1.1.1.1
I guess I have to go in the interface first to do that.
OK, so if I'm really connected to that physical switch,
I should be able to ping it.
And it's gonna ARP.
And then I have a successful ping.
So, that's it.
So to recap everything we did.
Step number 1 was to actually go to my physical device,
turn it on, configure it however I wanted to configure it
and then connect a physical ethernet cable
from one of the interfaces on my physical device
into the ethernet NIC card on my laptop
where I'm running GNS3.
So that completed the physical configuration.
Step number 2 was I started up GNS3.
I created my topology however I wanted.
And then the key component to connect these two together
was to use the Cloud node.
And so within the Cloud node
I just right clicked on it, I selected configure
and under the Ethernet tab right here
I ensured that this drop down box
was selecting my Local Area Connection
which is my LAN adapter.
Now I don't want two of them.
I'm not gonna worry about that for now.
Once I had that selected then the last piece of the puzzle
was to start up my router in this particular case.
Add a link.
Actually should do this before you start the router
while the router was still powered off,
add a link between it and the Cloud.
Optionally you can change the icon of the Cloud.
And then you start up your router.
Now before I finish, one last thing I want to talk about.
I mentioned that the Cloud and the Host are interchangeable.
Let me just drag the Host in here for just a second.
If I right click on Host
you'll see that it also has the option to
connect to various things here.
It's really no different.
The configuration is exactly the same.
So why would I use one over the other?
Well let's say that here, my actual lab,
right next to me I had,
let's say three physical switches.
I want to test out some things
like multiple spanning tress
and VLAN access lists and private VLANs and stuff,
and I sort of figure that
I need a minimum of three physical switches
to do all that stuff.
In that particular case
it would be appropriate for me to use the Cloud icon,
because my simulated environment is connecting
to a real world environment of more than one thing,
multiple devices.
Now on the flip side.
Let's say I really was just gonna
connect to, let's say, a AAA server.
Let's say I had a physical server
sitting on the desk next to me
that was running Windows 2000 or Windows R8
or you know, whatever,
and it had a AAA radius server inside of it
that I had up and running.
And then I was gonna connect to that.
Well I could still use the Cloud node
but it might be more appropriate in that particular case
to instead use the Host node.
Because really I am connecting to a Host, a server.
Really it's completely up to you.
They both do exactly the same thing.
So that concludes this particular video
on how to connect your GNS3 virtual environment
to a physical device.