- [Narrator] In this video I'd like to talk about
an alternative way of doing switching
in your GNS3 topology by using the EtherSwitch router.
And if you wanna practice IOS commands
that relate to switches,
this is what you're gonna wanna do.
So, before we actually look at how to do this,
let's talk about how do I get this
into my topology in the first place.
This is not a built in node,
this is a special IOS image
support on a certain range of routers
that give the routers this ability.
So, how do we figure that out?
Well, the first thing you're going to want to do
is go to GNS3.com.
And go ahead and log in...
And then from there you're gonna wanna click
on support followed by documentation,
and then from here, click on where it says
"Adding IOS Images".
We already saw this window before a couple of videos back,
when we were talking about what IOS images
were suitable for GNS3,
so I'm gonna go back to that exact same document
that we were looking at next time,
which is viewable right here,
from where it says "In this document".
We're gonna wanna click on those words,
which will bring up another document.
Okay, so, the EtherSwitch module
is an actual module that goes in a network module slot
within a router.
So, any of the routers that you see in this list
that support NMs or network modules
will support the EtherSwitch module.
So for example, look at the 1700 series.
It says it supports two sub-slots for WICs
and no network slots,
so if you get yourself a 1700 series IOS software image,
you will not have access to the EtherSwitch module.
So if we scroll down past all of these,
past the 7200s at the bottom,
it actually has a section right there
on Cisco Catalyst Switches.
And it says that as long as you can get an IOS image
that supports the 2600s, 3600s, or 3700s series,
then you will have access to the EtherSwitch module.
In my particular example in this video,
I'm going to be using a 3725 for the EtherSwitch.
Now one other thing that's important to know about this,
is notice it says that the EtherSwitch module,
because its not a hardware based switch,
like a Catalyst 6500 or a Catalyst 4500
or something like that,
it's not gonna support the full range of features
that you would have in a real physical switch.
And right here in this document
it actually tells you, if I zoom in here a little bit,
these are all the features which are not supported
by the EtherSwitch module,
so there are quite a bit of them,
and that's just a limitation of that particular module,
even if you had a real 3700 router
and you had a real EtherSwitch module plugged into it,
you would still have a serious limitation on these switches
right here, on these various features.
So, there's a lot of stuff in here,
and especially if you're a CCNA candidate,
I wanna point out some of the features
that unfortunately are missing from this device,
that you are gonna wanna have some practice with
if you can.
So number 1.
And I'm sure its somewhere here on this list,
I'm just not looking at it right now,
but when it comes to trunking, 802.1Q trunking,
you're gonna wanna learn how to configure
and monitor dynamic trunks that use DTP,
the Dynamic Trunking Protocol,
so in a real switch,
it would be switch port mode dynamic,
and then you'd select auto or desirable.
Switch port mode auto or desirable.
That's not available here.
In the EtherSwitch module all you can do
is statically configure an interface as a trunk
with Switch port mode trunk,
there is no dynamic option.
Another thing,
when it comes to EtherChannels,
you can create EtherChannels in here
but you cannot create dynamic EtherChannels,
so once again, with EtherChannel in a real switch,
you have a choice if you want to of either
using the port aggregation protocol or LACP.
Once again, that would be like
desirable or auto, or something like that.
Passive active.
Those keywords also, not available in an EtherSwitch module.
When it comes to VTP, the VLAN Trunking Protocol,
what I've noticed is that real switches,
and you'll see this in documentation,
if one switch is configured with a VTP domain name,
and then it trunks with a second switch,
there's a functional trunk here,
and the second switch has no VTP domain name,
it's empty, it's null,
the second switch can learn of the VTP domain name
from the first switch.
That's not gonna happen in this particular case.
I'm not exactly sure in the background why
that's not happening,
because these do support VTP to a limited extent,
they support VTP version 1 and 2,
not VTP version 3,
but still for a CCNA candidate,
pretty much all the VTP stuff you'd want to do
is support on here, but not the dynamic learning
of domain names.
At the CCNA level you have to learn about
Rapid Spanning Tree or Rapid PVST.
Unfortunately, these EtherSwitch modules
only support 802.1D or PVST normal,
PVST plus, with 802.1D they do not support
Rapid Spanning Tree, they do not support
Multiple Spanning Trees,
and MST is something you have to learn to configure
and troubleshoot at the CCNP level and above.
One big feature that's missing from here,
which is unfortunate,
because the CCNA a lot of times
is gonna hit you hard on this feature,
is port security.
When you're learning about switching,
one of the features you're expected to know
is port security, how to configure it,
the various different keywords and Gotchas
that go along with port security.
Unfortunately, this EtherSwitch module
also does not support port security.
Now when you get up to the CCNP level,
this big list here takes on even more relevance,
as there's a lot more features that are not supported here.
So, if you're at the CCNP level
studying for your switch exam or beyond,
like the CCIE level
and you need access to all these missing features,
unfortunately at that point,
you're gonna only have two options:
Either get yourself a real physical switch,
which is the ideal option,
and there are ways you can actually connect
a real physical switch into your GNS3 topology
if you need to do that,
or get your hands on L2IOU.
But even L2IOU doesn't have all the things supported
in a real switch,
there are some features in L2IOU that are not supported,
so if you want the full range of everything
you're gonna have to have a real physical switch.
So, now that we've spent enough time on talking about
what this thing can't do,
let's take a look at what it can do.
So we know now that any router
that supports network modules
will support this EtherSwitch module,
so what I'm gonna do if I haven't already done this,
I'm gonna go to Edit and Preferences,
under Dynamips I'm gonna click on IOS routers,
and I want to add a new router,
because if you had an EtherSwitch router,
it would show up here, you would see it in this list.
But we don't see one,
so I'm gonna click on new,
and I'm gonna use my existing image, 3725.
In this particular case I'm just gonna say,
C3725, let's say EtherSwitch.
But this is the key part, right here,
when adding this you wanna select this option
where it says, "This is an EtherSwitch Router,"
and actually by doing that it changes the name for you,
I didn't even need to change the name.
So that is the critical component, right there,
if you don't select that, that EtherSwitch network module
will not be available to you on the next screen,
so we need to select that.
And now when I hit next,
select the appropriate amount of memory,
which I think is 256 for this particular image,
and now you can see by default it populates
one of your network module slots with a 16 port
EtherSwitch module.
Now if you want to, if 16 ports is not enough,
you could populate it with another one,
or certainly if you wanna use this router
for routing as well as switching,
oh, let's put in a four port serial card as well.
And because this is a 3725,
we have some WIC slots available,
I'm just gonna leave these empty
because I don't care about those
for this demonstration.
And we're gonna wanna find an idle PC.
And this is normal, don't worry too much about this,
we just have to wait for about 30 seconds or so,
and then it should find an idle PC value
for this particular platform.
And there we go.
It has found an idle PC value,
which is what we were looking for,
so click okay, and finish.
And now we can see,
up in the available platforms,
now we have, if I expand this a little bit,
it actually won't let me,
we have an EtherSwitch router.
So click okay.
So now on this particular topology
which is the topology we just saw in the last video,
I'm going to accomplish the same thing,
but this time I'm gonna use the EtherSwitch router,
so I can have a little bit more experience
configuring IOS switching commands.
So click once again on your switching tab,
or switching button,
and now we have an EtherSwitch router,
so I'm just gonna drag and drop that into place...
Okay, so let's go ahead
and connect its interfaces.
Now let's talk a little bit about its interfaces
for just a second.
I'll zoom in here.
Because this is a 3725,
the fast Ethernet interfaces
that are on the main chassis, which you see here
are Fast Ethernet 0/0 Fast Ethernet 0/1.
Those are routed interfaces,
those do not belong to the switching module.
So you have to look under,
and you can see here,
which ones are included under the switching module,
and if you see that,
let's bring that up again,
you can see that slot 1 has the network module
with the 16 port EtherSwitch.
So in this particular case, ports 1/0 up to 1/15
will be my switching interfaces,
that's where I will find those.
So don't try to configure your switchport commands
on the first couple of interfaces,
because those Fast Ethernet interfaces
are router interfaces, not switching interfaces.
Now this one,
if I right click,
I don't wanna select configure,
this is not like the built in switch node
that we saw before,
I'm not gonna configure this thing via a GUI,
I'm gonna configure it via the actual command line.
So let's go ahead and start it up first,
'cause I won't even get the command line
if I don't start it.
Here we go.
And let's go ahead and right click and select console.
And here we are.
Wait for it to boot up a little bit.
Okay, now before I configure it,
I can go ahead and add my connections at least,
using the link tool,
so I'll click on that.
So here I'll select the very first switching port,
which is 1/0.
I'll connect that to PC 1.
And I'll keep doing it with the other ones.
And when I'm done here,
I will move the port designators around a little bit
so they are actually clear.
Alright, so that's that.
Let's go ahead and move this guy
so that everything lines up nicely...
Okay, now I can see my interface designations
a little bit more clearly at this point.
Okay, so in the last video,
in order to create our VLANs and create our trunks
and assign it to the ports,
it was all based on the GUI.
Well now I've actually got a router,
so I have to go in there and configure that.
So let's go ahead and start with
Fast Ethernet 1/0 and 1/1.
So because this is a router,
I can actually use the #int range command.
#int range fast 1/0 - 1/1.
#switchport.
#switchport mode access.
#switchport access vlan 1.
#no shut.
Now let's go back to 1/2 and 1/3
and let's put those into VLAN 2.
#switchport.
#switchport mode access.
#switchport mode access vlan 2.
And notice it created VLAN 2 just like you'd see
in a real switch.
#no shut.
#exit.
Now if I wanted to create a VLAN on this thing,
some of the earlier versions of GNS3
and earlier versions of software
said that in order to create a VLAN
you had to go into VLAN database mode.
And then from there type in your VLAN
or whatever it was,
but in reality you don't have to do that anymore.
Here from the global configuration mode
you can still create a VLAN.
It works.
Now the last step,
I want to create my 802.1Q trunk
right here on Fast Ethernet 1/4.
So notice when I do #switchport mode,
if this was a real switch you'd have access
to #switchport mode dynamic,
but that's not in right here,
so I can't select that.
So, #switchport mode trunk.
Also notice that with just a regular #switchport command,
one thing that's missing is #switchport port security.
The port security option is not available here
as I mentioned.
#no shut.
#exit.
And before I leave here, you do have a variety
of spanning tree commands available to you,
for practicing spanning tree,
and moving around your root bridge,
and practicing per VLAN spanning tree plus,
and all that good stuff.
Now one other thing that's sort of different in here,
if you were in a real switch
and you wanted to see what VLANs were available,
you would simply type show VLAN.
Well, that's not the correct command,
and actually it tells you up at the very beginning,
if I can go through there when it first came up,
right here it says "To view existing vlans,
use the command "show vlan-switch brief.""
Show vlan-switch brief.
And that's how I can see my VLANS
and the output is pretty much identical
to the output you would see
on a regular physical switch.
Okay, so nothing's showing up
under #sho interface trunk,
which is a little bit suspicious,
so let's take a look.
According to my topology here,
interface Fast Ethernet 1/4 should be trunking,
it's possible it's not coming up
because the other end of the line is currently down.
Router 1 right now is in a shutdown state,
so that might be why Fast Ethernet 1/4's not coming up.
So let's just bring everything else up,
give it just a couple seconds in the background,
for Router 1 to finish loading.
#sho run int fast 1/4.
Okay, switchport mode trunk, duplex full, speed 100.
That looks good, it is not shut down.
#sho int fast 1/4,
so what about the physical layer properties.
Ah, okay, so here we have a problem.
Fast Etherner 1/4 is up, but the line protocol is down,
most likely because something
is not configured correctly on the router's side.
So let's just go back to the router here
and get that working.
So here's my router.
#sh run | begin interface FastEthernet0/1.
Speed is 100. Full duplex. Looks like that should be okay.
And our sub interfaces are correctly configured,
let's just take a look at the actual status
of that interface.
Okay, it says it's up, line protocol is up,
now these EtherSwitch modules do support
the Cisco discovery protocol,
so #sho cdp neigh.
Okay so we do have some problem here,
because router 1 is not seeing the EtherSwitch module.
Let's just double check everything.
So once again, start with the topology summary window.
Is everything green, do we see any red lights?
Nope, everything's green,
everything says its on.
Okay, so I can get out of there.
Verify that my interfaces are correct,
so if I just hover over the switch,
the EtherSwitch module,
and take a look at the interfaces,
let's see here...
So, it looks like,
if I scroll over that again, okay,
so Fast Ethernet 1/4,
and we can see right down there is connected
to Router 1 on Fast Ethernet 0/1, so that is correct.
Alright, let's save my project before I go any further.
Sometimes, what I've seen is you have to play around
with the speed and the duplex of the interfaces
to get everything lined up correctly,
so even though we saw,
let's go ahead and do this again.
So we saw on Router 1...
Let's do that again.
Router 1, we see that he is full duplex, 100 megabits
per second, which I believe is the exact same thing
as the EtherSwitch.
Ah, Auto-duplex, Auto-speed.
Okay, so we're having a mismatch here,
because on one side it's hardcoded
for full duplex and speed,
on this side it is using auto-negotiation.
So let's just change that.
Shut the interface down.
Change the speed to 100.
Change the duplex to full.
#no shut.
And hopefully that will fix our problem.
Ah there we go, that looks good.
Has become .1Q trunk.
#sho int trunk.
And now confirms it, that our interface
is actually in trunking state.
So that concludes this particular video
on the EtherSwitch module,
as you can see, to recap what we talked about.
Number 1: You have to select an IOS image
for a router that supports network modules,
and I showed you on the GNS3 website
how to get to that page that specifically
talks about the routers that support that.
So get a hold of the correct IOS image.
Number 2: Import that IOS image into GNS3
and when you get to the appropriate screen,
click that little box that says,
"This is an EtherSwitch module."
That was required.
Number 3: Within GNS3 itself,
once that router's there, once that switch is there,
you can now go to the switching section,
and you'll see it available,
as an EtherSwitch router,
just drag and drop that into your topology,
and then number 4:
just go into the console that,
just like you'd go into the console
of any other router in your device,
and start configuring the appropriate interfaces
in the network module as switchports,
and configure your spanning tree
and everything else that you need to do.
So that concludes this particular video
on how to use switching in GNS3.