(musical sound effects)
- [Keith] In this lesson I'd like to start
by talking about one of the two ways
that you can incorporate switching into your
GNS3 simulated network topology.
Because chances are, I'm guessing that if you're studying
your CCNA, NP, or anything else, you're gonna need
to be able to practice switching along with that.
Now as far as switching is concerned,
there's two basic ways to do that.
There's several advanced ways using L2, IOU,
and other stuff I'm not gonna get into in this series,
but there's two basic ways that you can do that
if you're sort of a new or intermediate GNS3 user.
One is to use what's called a built-in switch node,
and the other is to import in a router that acts
like a switch called an ether switch.
So in this particular video,
I'm gonna be focusing in on the first one,
built-in switch node, so let's talk a little bit about that.
So here is my GNS3 topology,
and in this particular case it's already
fully functioning and built,
and I've used a built-in switch node,
so this is what the built-in switch node looks like,
and where you would get that from,
is from right here in the device notes section.
This section right here is where you find
your switches, so here's the various routers
that are available to you,
and here's where you find your various layer two switches.
And the Ethernet switch is the one that we're gonna be
focusing in on today,
and you can just drag and drop that,
just like anything else.
Now the Ethernet switch, if you choose to use that,
one of the nice things about that is,
like I said it's a built-in node,
built in to GNS3 so, it doesn't require any
IOS, it actually is not even configured via
command line at all, you just configure it
via a very basic GUI.
Now this built-in switch node, like I said,
very basic device.
Really the only thing you're ever gonna want to use it for,
is one of two things, either segmenting your network
into different VLANS, or I guess it could be an and,
using 802.1Q trunking.
So those are really the only two things.
This built-in switch node does not do anything else.
It does not do any of the CISCO stuff like DTP
or VTP, or CDP, none of that.
As a matter of fact, these switching nodes
don't even do Spanning Tree, so be very careful about that,
because if you actually do put two or more of them
in your topology and you connect them together,
you can very quickly create a bridging loop,
because there's nothing to prevent the bridging loop,
there is no Spanning Tree in here,
so that is something to be wary of.
So in this particular environment,
I'll go ahead and get rid of it by just right clicking
on it and then selecting delete,
because I don't need that one.
In this particular case, all I'm doing is I've got four PC's
which are segmented into two different VLANs,
a VLAN for payroll, and a VLAN for human resources.
And maybe what I want to do, maybe the objective of this lab
was simply to practice the router on a stick,
so I didn't really care about practicing the switch,
I just wanted to practice how to create a router
on a stick for the router.
So maybe that was my objective.
Now in this particular case,
all this is already up,
the router has already been pre-configured,
and what I want to do is show you,
how did I get to this point?
How did I get this switch in here, and how did I configure
it in such a way that two of its interfaces,
these two right here, would be in one VLAN, like VLAN one,
and these two interfaces right here would be in a completely
different VLAN, and this interface right here
was 802.1Q, because that's what was necessary
in order to make this topology work.
So how did I do it?
All right so let's start, let's go back a little bit,
and start by getting rid of the switch.
Right click it, select delete, yes.
And when I delete it, all of the links I've had
to various devices are also deleted.
Okay so, let's go back into here
and open up my switching section, there we go,
and I'll drag and drop my Ethernet switch
into the topology.
All right so there it is.
And notice that as a built-in node,
the moment you drag and drop it, notice over here,
on the right, how it's already green.
So it's already on, it's already activated,
there's no shutting down of this particular device,
it's just always there.
Okay so now if I right click on it,
remember this doesn't have any kind of command line,
so the way you would actually configure its interface
is by selecting the configure option,
the very first option.
So as you can see, what it comes up with by default,
are eight interfaces, all of which are static access ports,
all of which are in VLAN one.
If I wanna add a new interface,
you can see it's already set up and ready to go,
so if I click the add button, it will add
interface number nine, or port number nine,
there will be an access port, and it'll be in VLAN one,
so boop, there we go.
Now if I wanna add another interface,
interface number ten, maybe I want that to be
in a different VLAN, so you can just change that,
hit add, boop, there you go again.
Maybe I wanna add a new interface,
interface 11, and I want it to be 802.1Q,
so you can see your options here from the drop down menu.
Now when I make this as 802.1Q port,
the VLAN referenced here, is gonna be the native VLAN.
So I might not want VLAN five as the native VLAN
for my 802.1Q trunk, so I'll set that back down to one.
And you can see here how it's been created.
So adding new interfaces, pretty easy.
I've actually read that this switch can support
like up to 10,000 VLAN's, some crazy number.
Now, what if you want to modify an existing port?
That, you cannot do.
So for example, let me, first of all
you have to double click on a port to select it,
double click, double click.
And if I wanted to change port number one
to be an access port in VLAN two, you might think
okay, we'll just change that, and then hit apply.
But look, nothing happened.
It's still an access port in VLAN one,
it didn't change anything.
Similarly, if I wanted to change one of these existing
ports into an 802.1Q trunk, that wouldn't work.
So what's the moral of this story?
Well, if you want to take an existing port
and change its characteristics,
you have to delete it first.
So I'm just gonna delete everything,
I'm gonna start with port number one,
and delete everything that's in there.
Okay all the ports are gone,
and now for the purposes of my topology,
what I'm gonna do is, I'm gonna have ports one and two
leading to these two PC's and VLAN one.
I'll have ports three and four leading to these PC's
in VLAN two, and then I'll have port number five
as an 802.1Q trunk.
So once again right click and select configure.
So port number one is already by default
gonna be an access port in VLAN one,
so I'll just hit add, port number two
I'll just add that, that's okay.
Port number three, before I create it, that's the key,
before you create it, I'm gonna change the VLAN to two,
add it, port number four I also want to be in VLAN two,
so add it.
And by the way, you can also see right here
that you can change the name of the switch, if you wish.
And then port number five, I'm gonna have that
as an 802.1Q port, and I'm gonna have
the native VLAN as one.
And then hit apply, and then okay.
So now it's ready.
Another way that you can verify,
if you're taking a look at a switch,
an Ethernet switch, and you wonder how it's configured,
all you have to do it hover over it.
So put your mouse over it, hover there,
and then it'll tell you.
Now in this particular case,
it's saying the ports are empty because it's not connected
to anything yet.
So once I actually connect those ports to something
and then I hover over it,
I'll actually see a lot more stuff.
I'll see if it's trunking, I'll see if it's in a VLAN,
I'll see all that.
So, let's do that next.
So now I'm gonna go to my connect or add a link tool,
just click that.
All right, so I'll select port number one,
I'll just click on port one,
and I'll go over here to my first PC
and select his Ethernet.
Select port number two, go to my second PC,
and I'll just keep doing that for the remaining PC's.
And also in this particular lab,
I'm using another built-in node,
the virtual PC simulator.
Not gonna talk about that in great detail right now,
we'll get into that in a subsequent video.
And then lastly, we'll take port number five
which has already been pre-configured as a trunk,
and connect it to fast Ethernet zero one on my switch,
on my router, that is.
Deselect the link tool,
because I don't want to add any more links.
Some of this stuff looks kinda messy,
which is nice because I can drag this stuff around,
to make it a little bit more easily visible.
So if for some reason I wanna take a screenshot of this,
or just for my own benefit, I can actually read it
a little bit easier.
Now let's just move the name of the switch down here.
And now we should be good to go.
Now in this particular case,
the router's already pre-configured,
and now if I hover over the switch at this point,
and zoom in there, now you can see,
for example, port one is access mode in VLAN one,
port three is in access mode, VLAN two,
and port five is .1Q, with a native VLAN of one,
that tells you what it's connected to.
So that's sort of a nice way to get
a status update on the device.
Everything is green right now,
so let me go into one of my virtual PC's and make sure
it's got an IP address.
And it does, let's see if he can ping his counterpart,
PC two, who's also in the payroll department.
Not reachable, okay, so let's check PC two.
Show IP.
All right, so he was, he does have the correct IP address.
Actually, I have seen this before,
where everything is set up correctly,
but they're not ping-able,
and what I've had to do
in this particular situation actually is,
actually before I disconnect,
I wanna save my configuration on the PC's.
Close this, and what I've seen,
what I have to do to make this work is basically
to shut everything down, so click the stop all devices
button, up here.
And you can see that stops everything but the switch,
and now turn everything back on again.
Let's go back into my PC.
Show, show IP.
He still has his IP address, now let's see if he can ping
the other PC in the same VLAN, and it works.
Not sure why you have to take that extra step,
but in the particular case it was necessary
to stop and restart everything.
And so that's the basics of the Ethernet switch,
real simple, as you can see once again,
just right click it, hit configure,
and then you can modify the various ports.
Now as you can see, there's a few other options
available to you here when you right click,
such as change the host name,
which is something we're actually able to do
in that GUI, change the symbol,
if you wanna change it from this switch
to one of the other switch types you can.
Capture, if I selected this I could actually
do in a wireshark capture,
and it would first prompt me for what interface
I want to capture on,
and then once it's started,
every packet going in and out
would be displayed in wireshark,
and I'll go ahead and do that in a subsequent video
where I can focus exclusively
on wireshark interaction with this.
And raising and lowering one layer,
we've already talked about that when I talked about
adding circles or adding squares into your topology.
And then of course, there is delete.
So that concludes this particular section
on the built-in switch node.
In the next section, we're gonna look at
actually dragging and dropping a router
that has a special module in it called
the ether switch module.
And that's gonna be useful for you if you actually
wanna practice IOS switching commands,
like Spanning Tree, trunking,
PortFast, and a range of other stuff.
So we'll see that in the next video.