WEBVTT

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 So in the previous video, I talked about
 the theory of what is meant by

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 router on a stick.

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 And once again, what I meant by that is
 simply a router that has one physical

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 cable, one physical link
 connecting to a switch.

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 That switched port is configured as
 trunking, which means the router's

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 interface is supporting multiple subnets,
 multiple VLANs on the switch

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 side, multiple subnets on
 the router's interface.

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 And the subnets were broken out by using
 the use of subinterfaces on your

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 fast, ethernet physical interface.


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 So we talked about the theory
 of how that works.

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 Now let's look at how we actually configured
 that and how we would monitor

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 and troubleshoot that.

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 So those are the goals for
 this particular video.

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 I'm going to talk about how
 to configure the router.

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 I'm going to show you how to do that
 and how to monitor routing between

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 the VLANs. All right, so for this,
 I have a topology already pre-built

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 in packet tracer.

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 And I chose packet tracer because it's
 something that you as the learner

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 can very easily replicate.

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 You can download packet
 tracer for free.

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 If you haven't already done that, just
 go to Google and type in Cisco

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 packet tracer download.

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 And once you sign up for Cisco's Networking
 Academy, which does not mean

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 you have to take their classes or go to
 a brick and mortar school or anything

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 like that, all you're basically doing
 is just registering on their website.

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 Then you can download this free
 tool called packet tracer.

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 And you can create a topology
 like this very, very easily.

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 So what I've already done, as you can
 see here, is I have created two

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 VLANs. I've got VLAN2 and VLAN1.

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 I have my switch here who has
 some interfaces in VLAN2.

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 He has some interfaces in VLAN1.

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 I have some hosts
 within each VLAN.

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 And if I hover over those hosts, you
 can see what their IP addresses are.

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 I've made it very, very simple.

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 So for example, this host right here,
 if I go to his config, he is, well,

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 let's see here. Last time I checked when
 I hovered over it at work, let's

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 see here, let's try it again.

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 There we go. All right.

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 So you can see that host is 1111.

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 His default gateway is pre
-configured as 1112.54.

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 This other host over here in
 the same VLAN, he is 1112.

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 Don't have a gateway set on him, but
 I'm not really going to be using

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 that for a demonstration.

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 Over here in VLAN2, if I look at
 PC2, his IP address is 2221.

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 And his default gateway
 is 2222.54.

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 Now, where are these IP addresses of
 the default gateway, the 1112.54

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 and the 2222.54?

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 That is pre-configured
 on my router.

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 So if I click on my router, and if we
 go to config, actually the command

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 line interface, and we take a look
 at the command line interface right

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 here, make this a little bit larger
 so you can see it there.

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 When I issue a show running-config command,
 here you can see I have already

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 created my router on a stick.

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 Now, I did a little bit differently
 because in my particular case, my

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 two VLANs, as you can see right
 here, are VLAN1 and VLAN2.

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 Now, because VLAN1 is the native VLAN,
 when this interface right here

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 on the switch is configured as a trunk,
 I know that anything that this

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 guy sends going to his default gateway
 is not going to be tagged.

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 That is the native VLAN, it will
 go in its pure native format.

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 Now, anything that this PC sends going
 to his default gateway, well, that

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 will be tagged with the .1Q tag of two,
 because VLAN2 is not the native

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 VLAN. So knowing that, I actually don't
 have to create a sub-interface

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 to handle the VLAN1 traffic.

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 So let me take a look at
 my router once again.

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 You can see that my VLAN1 traffic is
 actually going to be handled by my

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 main physical interface.

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 You can see right here that under FastEthernet00,
 I have actually put

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 an IP address. So any Ethernet frames
 that hit that physical interface

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 that do not have a tag will be inspected
 and handled by that physical

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 interface. Now, if a frame comes in that
 has a .1Q tag of two, well, then

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 in that case, that will be redirected
 internally to this sub-interface

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 right here. And that sub
-interface will handle it.

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 So you can see I still have
 a router on a stick.

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 I still have a router with one physical
 interface, FastEthernet00, that

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 one physical interface has
 multiple subnets on it.

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 I shouldn't say the physical interface
 does, but the physical interface

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 has one subnet, and then I've divided it
 out into this case, a sub-interface.

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 And the sub-interface gave me the ability
 to add a second subnet or IP

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 network to the same
 physical cable.

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 Now, of course, if I had 30 or 40 VLANs,
 I would have created more of

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 these. I would have created
 more sub-interfaces.

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 And each sub-interface would have
 a different number after the dot.

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 Each sub-interface would have this
 encapsulation .1Q command, and the

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 number after the .1Q would be representative
 of the VLAN that that sub

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-interface was handling.

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 And then each unique sub-interface
 would have their own IP address in

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 an IP subnet that was appropriate for
 the VLAN that sub-interface was

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 dealing with. Okay, so notice
 something else as well.

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 So now in this particular case, we know
 that this PC here, that his default

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 gateway is 111.254, which is on the
 physical interface of this router,

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 .254. We also know that this guy right
 here, his default gateway, is 222

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.254, which is located right
 here on a sub-interface.

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 222.254. Now, even though this router,
 for all intents and purposes, even

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 though it looks like one interface,
 he is thinking that he has two, the

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 physical and the sub-interface, both
 of those need to have a MAC address.

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 Because both of these guys need to discover
 the MAC address of their default

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 gateway, so they can send Ethernet
 frames to that router.

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 Now, as it so happens, when you take
 a physical interface on a router,

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 a fast-ethinet interface, we're not
 talking about WAN interfaces here,

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 we're talking about LAN interfaces, when
 you take your fast-ethinet interface

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 and you subdivide into sub-interfaces,
 the router will just copy its MAC

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 address from its physical interface
 and just replicate that across all

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 the different sub-interfaces.

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 And we can see that here.

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 Show interface, fast-ethinet 00.

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 All right, so notice, I don't expect
 you to memorize his MAC address,

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 but notice his MAC address ends
 with the digits of 3001.

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 Okay, so notice that, 3001.

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 Now, let's compare that against
 his sub-interface of .2.

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 Also, 3001, so you can see here that the
 MAC address of the physical interface

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 has just been replicated
 across the sub-interface.

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 Here's the physical interface MAC, here's
 the is not just a packet tracer

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 thing. If you were to do this in a
 real hardware router, you would see

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 the exact same thing, that your sub
-interfaces use the exact same MAC

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 address. Now, you might be wondering,
 well, wait a second, Keith, how

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 can a router's interface, how can a
 router have multiple interfaces, all

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 of which have the
 same MAC address?

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 Wouldn't that get things confused?


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 Not really, because if we take a look
 at this right here, remember, maybe

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 this is my main physical
 interface right here.

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 Let's have this box represent
 fast-ethinet 00.

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 Now, let's say his MAC address is, well,
 let's do our previous one, 301.

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 There's a lot more in front
 of that, but colon 301.

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 That's the last four hexadecimal
 characters.

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 Now, let's say that I go and I subdivide
 this into three sub-interfaces,

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 and that's what these three
 sub-boxes are for.

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 So we've got 00.2, we have 00.3, and
 00.4, and let's say they all get

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 replicated the exact
 same MAC address.

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 Well, if three frames come in, let's
 say here's frame number one, frame

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 number two, frame number three, and
 if all three of these have the same

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 destination MAC ending with 001, remember,
 that's just the last few characters

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 of the MAC address.

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 I'm not going to waste your time writing
 in an entire MAC address in all

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 48 bits. How is it going to know
 which sub-interface to use?

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 Well, remember, each one of these sub
-interfaces has got that .1q command.

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 It's got that .1q command in there,
 so let's write that in there.

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 So this one right here might
 have encapsulation .1q2.

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 This one here has encapsulation .1q3,
 and this one has encapsulation .1q4.

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 So when a frame comes in, if this frame
 here has a .1q tag in it for 2,

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 then even though it's hitting the physical
 interface of FastEthernet 00,

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 the router will be smart enough to know,
 oh, I need to reroute that internally

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 in my own mind to this particular
 sub-interface right here.

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 And same thing with
 the next frame.

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 The next frame that comes in with a
 .1q tag of three, so this is an 802

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.1q tag that I'm writing here
 inside your ethernet header.

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 The router will be smart enough to know
 that even though it was received

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 on FastEthernet 00, it needs to be rerouted
 internally to sub-interface

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 FastEthernet 00.3.

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 And of course, the same thing would
 be true with this third one right

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 here, if there was a tag on that.

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 So it's okay that all these sub-interfaces
 share the exact same MAC address

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 as the physical interface, because
 based on what the frame looks like

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 when it's initially received, there will
 be something in that frame, namely

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 a .1q tag, which helps the router to
 identify which sub-interface should

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 be using or should be
 receiving that frame.

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 Now let's go back to Packetracer
 right here.

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 Okay, so we know that this sub-interface
 ended with something, something,

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 something, something, .300001.

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 So we can put that in there.

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 All right, so that
 is the MAC address.

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 Let's get rid of that.

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 Oh, I did not want to undo that.

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 So let's bring that back.

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 I'll get rid of that one.

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 Sometimes in Packetracer, when you try
 to put in notes, it's kind of hard

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 to line up the note exactly
 where you want to be.

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 Okay, so MAC 30001.

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 All right, so we've got that.

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 Okay, so one other reason why I like
 using Packetracer, at least at the

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 CCNA level, is because it has a
 built-in Packet capture program.

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 You see, if we were using real routers
 and switches, we'd have to somehow

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 insert a hub, get some sort of laptop
 into our topology that has got wire

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 shark. We don't have to deal
 with all that with this.

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 All right, so here's
 what I'm going to do.

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 On PC zero, remember that guy is 1111,
 and you can see it right there.

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 I'm going to open up a prompt.

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 I'm going to make this
 as small as possible.

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 And I'm going to ping something
 in a different B-land.

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 So what I'm going to do is I'm going
 to ping from PC one to PC two.

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 And we're going to see that in order
 for that to work, in order for that

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 to work, this is minimize this for
 a second, PC one will first need to

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 ARP for his default gateway,
 which is 111254.

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 And he will learn this MAC address right
 here when he gets the ARP reply.

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 Then he will send his ping up
 this trunk to the router.

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 We will see it going to the destination
 MAC address of 301.

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 Once it gets to the router, the router
 will have to put that ping on hold

0:13:18.940000 --> 0:13:21.320000
 for a second while
 it turns around.

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 And the router ARPs for
 this host right here.

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 Once that ARP reply comes back, then
 the router can take this ping right

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 here and send it down here back
 down on the trunk to this guy.

0:13:38.700000 --> 0:13:43.420000
 So we'll see how the ICMB comes up, gets
 rerouted from one interface down

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 to a sub-interface,
 and then goes down.

0:13:46.280000 --> 0:13:47.700000
 So let's go ahead and
 watch that in action.

0:13:47.700000 --> 0:13:49.420000
 So now we're going to
 see how do we monitor?

0:13:49.420000 --> 0:13:54.940000
 How do we monitor interv
-land routing?

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 Well, basically you have to
 edit filters right here.

0:13:58.520000 --> 0:14:00.560000
 We're going to select
 ARP and ICMB.

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 Those are the only types of packets
 we want to see here in this.

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 Now let's go ahead and
 bring this back up.

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 Let's get our ping ready.

0:14:11.320000 --> 0:14:16.520000
 All right, and let's start
 it out, auto capture.

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 Okay, so right here.

0:14:21.360000 --> 0:14:23.740000
 So here's the ARP request.

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 You can see right here in the upper
 right ARP request, where the PC is

0:14:27.380000 --> 0:14:28.280000
 ARPing for his default.

0:14:28.280000 --> 0:14:31.740000
 Okay, we know that's because it's a broadcast
 that was flooded out everything

0:14:31.740000 --> 0:14:36.440000
 in VLAN one. Now the router is responding
 with an ARP reply that's a unicast

0:14:36.440000 --> 0:14:38.780000
 that's going directly
 back to PC zero.

0:14:38.780000 --> 0:14:43.460000
 Once PC zero receives that ARP reply,
 he can now take his ICMB packet,

0:14:43.460000 --> 0:14:45.020000
 which is in red here.

0:14:45.020000 --> 0:14:48.920000
 He now knows what destination MAC
 address to send it to, the router.

0:14:48.920000 --> 0:14:52.380000
 So now that package, you can see here
 that ICMB is going up the trunk

0:14:52.380000 --> 0:14:54.540000
 to the router. The router gets it.


0:14:54.540000 --> 0:14:58.160000
 Here's where he routes it from his physical
 interface to his sub interface.

0:14:58.160000 --> 0:15:01.700000
 Now the router says, okay, I need to
 ARP for the destination because I've

0:15:01.700000 --> 0:15:04.120000
 never talked to PC two before.

0:15:04.120000 --> 0:15:07.700000
 So now the ARP, the router sent
 an ARP request onto VLAN two.

0:15:07.700000 --> 0:15:08.820000
 It was a broadcast.

0:15:08.820000 --> 0:15:12.800000
 It got flooded. PC two sends
 an ARP reply back.

0:15:12.800000 --> 0:15:15.860000
 We can see here this is the
 ARP reply coming back.

0:15:15.860000 --> 0:15:17.840000
 Now the router gets
 that ARP reply.

0:15:17.840000 --> 0:15:20.400000
 He knows what destination MAC
 address to send that ping to.

0:15:20.400000 --> 0:15:24.180000
 So now we can see the color
 changes a little bit.

0:15:24.180000 --> 0:15:27.240000
 Now he's going to send
 the ICMB packet.

0:15:27.240000 --> 0:15:32.020000
 And now the ICMB continues.

0:15:32.020000 --> 0:15:34.440000
 Let's just watch the second
 one right here.

0:15:34.440000 --> 0:15:38.620000
 ICMB goes up. And now the router can actually
 route it onto the sub interface

0:15:38.620000 --> 0:15:43.860000
 for VLAN two. Send it back
 down that trunk to PC two.

0:15:43.860000 --> 0:15:47.500000
 PC two will get that ping.

0:15:47.500000 --> 0:15:51.580000
 Now PC two will respond with an ICMB
 echo response, sometimes called an

0:15:51.580000 --> 0:15:55.960000
 ICMB echo reply, which once again
 has to go to his default gateway.

0:15:55.960000 --> 0:15:59.460000
 So there goes up the
 trunk to router zero.

0:15:59.460000 --> 0:16:03.400000
 Router zero just received it on
 fast ethernet zero zero dot two.

0:16:03.400000 --> 0:16:06.740000
 He's now routing it back onto the physical
 interface, which is responsible

0:16:06.740000 --> 0:16:07.920000
 for VLAN one traffic.

0:16:07.920000 --> 0:16:11.520000
 And it goes back downstream
 to PC zero.

0:16:11.520000 --> 0:16:18.960000
 Let's go ahead and stop
 that for a moment.

0:16:18.960000 --> 0:16:23.100000
 So this is the first thing that we've
 created from himself 111 going to

0:16:23.100000 --> 0:16:29.160000
 two to two one. But he didn't know what
 the MAC address was of his default

0:16:29.160000 --> 0:16:34.260000
 gateway. So right here we can see
 PC zero creating an ARP request.

0:16:34.260000 --> 0:16:39.800000
 If we look in the outbound PDU
 details we can see right here.

0:16:39.800000 --> 0:16:45.180000
 So the type zero x eight oh six that
 is for ARP that is the ethernet type

0:16:45.180000 --> 0:16:50.040000
 code for ARP. And we can see here operational
 code one that is for an

0:16:50.040000 --> 0:16:53.960000
 ARP request. And here it
 says, Hey, I am 111.

0:16:53.960000 --> 0:16:56.420000
 I'm the PC. Here's my MAC address.


0:16:56.420000 --> 0:17:00.540000
 My target is the router 111 254.

0:17:00.540000 --> 0:17:04.500000
 And we can see right here that the
 target MAC address is empty because

0:17:04.500000 --> 0:17:06.960000
 that's what PC zero is
 trying to resolve.

0:17:06.960000 --> 0:17:10.700000
 So there's the ARP request
 that he created.

0:17:10.700000 --> 0:17:15.280000
 Now we can see that ARP request
 was last at PC zero.

0:17:15.280000 --> 0:17:17.760000
 Now it's at the multi
 layer switch.

0:17:17.760000 --> 0:17:21.580000
 And we can see destination
 MAC address all F's.

0:17:21.580000 --> 0:17:23.460000
 So that multi layer switch
 is going to flood it.

0:17:23.460000 --> 0:17:27.080000
 So we can see here with a multi layer
 switch floods it out to PC one who

0:17:27.080000 --> 0:17:28.780000
 doesn't really care about it.

0:17:28.780000 --> 0:17:30.540000
 And he floods it out
 to the router.

0:17:30.540000 --> 0:17:37.920000
 Now the router gets that and he's going
 to create an ARP reply outbound

0:17:37.920000 --> 0:17:43.820000
 PDU details. Notice zero x eight
 oh six that's for ARP.

0:17:43.820000 --> 0:17:48.480000
 But my op code is now
 two for an ARP reply.

0:17:48.480000 --> 0:17:53.060000
 And here the router is saying,
 Hey, my name is 1112 54.

0:17:53.060000 --> 0:17:55.060000
 You were looking for
 my MAC address.

0:17:55.060000 --> 0:18:01.260000
 There it is. And he is sending it to
 the target of the laptop of PC zero.

0:18:01.260000 --> 0:18:04.460000
 That is the ARP response.

0:18:04.460000 --> 0:18:07.420000
 Here are that ARP response
 guest to PC zero.

0:18:07.420000 --> 0:18:11.840000
 Now PC zero can take
 his ICMP packet.

0:18:11.840000 --> 0:18:17.860000
 If we look at the outbound PDU details,
 notice the destination address.

0:18:17.860000 --> 0:18:21.060000
 So here's the IP packet
 itself, the ICMP.

0:18:21.060000 --> 0:18:27.300000
 And we can see it's coming from
 PC one going to PC two.

0:18:27.300000 --> 0:18:28.720000
 So that's the ultimate
 destination.

0:18:28.720000 --> 0:18:30.200000
 But look up here at layer two.

0:18:30.200000 --> 0:18:36.060000
 In layer two, the destination MAC address
 is our router that we just ARPed

0:18:36.060000 --> 0:18:39.600000
 for ending with three
 zero zero one.

0:18:39.600000 --> 0:18:43.520000
 So now that ICMP packet can go out
 on the wire because it has the MAC

0:18:43.520000 --> 0:18:45.380000
 address of where it needs to go.

0:18:45.380000 --> 0:18:49.120000
 Goes from PC zero to the
 multi layer switch.

0:18:49.120000 --> 0:18:51.080000
 The multi layer switch
 switches it.

0:18:51.080000 --> 0:18:51.980000
 He does not flood it.

0:18:51.980000 --> 0:18:54.460000
 He forwards it directly
 to the router.

0:18:54.460000 --> 0:18:58.820000
 Here the router gets it.

0:18:58.820000 --> 0:19:02.740000
 Okay. So now at this point,
 the router has to ARP.

0:19:02.740000 --> 0:19:05.980000
 The router says, okay, I just got something
 going to two two two one.

0:19:05.980000 --> 0:19:09.380000
 However, I've never spoken
 to two two two one before.

0:19:09.380000 --> 0:19:13.320000
 I need to resolve the MAC address of
 PC two, which is two two two one.

0:19:13.320000 --> 0:19:19.240000
 So here we see. Once again, opcode
 zero zero zero one ARP request.

0:19:19.240000 --> 0:19:21.200000
 This time it's the router.

0:19:21.200000 --> 0:19:25.040000
 Hey, I'm your default gateway two two
 two two two fifty four two two two

0:19:25.040000 --> 0:19:27.260000
 one. Do you exist?

0:19:27.260000 --> 0:19:29.640000
 I need to know what
 your MAC address is.

0:19:29.640000 --> 0:19:35.880000
 So that ARP request gets received by
 the multi layer switch, who in turn

0:19:35.880000 --> 0:19:39.960000
 floods it to PC two and PC three.

0:19:39.960000 --> 0:19:43.240000
 PC two sends an ARP reply.

0:19:43.240000 --> 0:19:47.380000
 Now at that point in time, it's
 too late for our initial ICMP.

0:19:47.380000 --> 0:19:48.760000
 That first ping.

0:19:48.760000 --> 0:19:50.760000
 So remember what happened here?

0:19:50.760000 --> 0:19:55.440000
 What happened was after PC zero had
 ARPed, he sent his first ping up to

0:19:55.440000 --> 0:19:57.840000
 the router. Well, a ping
 doesn't last forever.

0:19:57.840000 --> 0:19:59.740000
 A ping has a lifetime.

0:19:59.740000 --> 0:20:04.000000
 So let's just make let's just say
 this right here is the ICMP ping.

0:20:04.000000 --> 0:20:09.620000
 Well, while the router was ARPing and
 getting an ARP reply back, this

0:20:09.620000 --> 0:20:11.460000
 thing timed out.

0:20:11.460000 --> 0:20:13.240000
 So that's why we see the first.

0:20:13.240000 --> 0:20:17.240000
 So that's why a lot of times when you do
 a ping, your first ping is unsuccessful

0:20:17.240000 --> 0:20:21.060000
 because all this ARP is happening
 in the background.

0:20:21.060000 --> 0:20:27.640000
 But now we see right here, the
 PC PC zero is now trying again.

0:20:27.640000 --> 0:20:30.220000
 He's creating his second
 ICMP packet.

0:20:30.220000 --> 0:20:33.080000
 This one will make it all the way through
 because now everybody knows

0:20:33.080000 --> 0:20:34.440000
 what they need to know.

0:20:34.440000 --> 0:20:43.900000
 We can see here PC zero, he's sending
 it to his default switch.

0:20:43.900000 --> 0:20:47.460000
 The switch switches it
 out to the router.

0:20:47.460000 --> 0:20:49.900000
 The router gets it.

0:20:49.900000 --> 0:20:52.640000
 Now here it is from the router going
 to the multi layer switch.

0:20:52.640000 --> 0:20:59.700000
 So now we can see the destination MAC
 address is PC two, going to PC two.

0:20:59.700000 --> 0:21:01.860000
 And then it gets routed.

0:21:01.860000 --> 0:21:03.720000
 And then the whole thing
 happens in reverse.

0:21:03.720000 --> 0:21:08.200000
 The ICMP packet comes back to the router,
 gets routed from the sub interface

0:21:08.200000 --> 0:21:12.740000
 of zero zero dot two back
 to the physical interface.

0:21:12.740000 --> 0:21:16.040000
 And then it goes out to PC zero.

0:21:16.040000 --> 0:21:21.880000
 So that is how we actually configure
 and monitor inter VLAN routing.

0:21:21.880000 --> 0:21:24.040000
 Now what are some other things you
 could do if you were doing this on

0:21:24.040000 --> 0:21:27.680000
 a real router? How would we know the inter
 VLAN routing was actually working?

0:21:27.680000 --> 0:21:29.200000
 Well, there's a couple
 of things we could do.

0:21:29.200000 --> 0:21:33.240000
 Let's go ahead and go back
 to regular mode right here.

0:21:33.240000 --> 0:21:37.660000
 So one thing you could do is you could
 go onto your router, go onto the

0:21:37.660000 --> 0:21:43.620000
 command line, and take a look at your
 interfaces with the show interface

0:21:43.620000 --> 0:21:47.800000
 command. So for example, show interface
 fast ethernet zero zero.

0:21:47.800000 --> 0:21:55.860000
 And what you're looking for here are
 packets input and packets output.

0:21:55.860000 --> 0:21:58.820000
 So let's do another ping.

0:21:58.820000 --> 0:22:09.100000
 All right, so let's say for every ping
 the PC zero creates, we should

0:22:09.100000 --> 0:22:12.300000
 see these numbers increment
 right here.

0:22:12.300000 --> 0:22:18.380000
 Let's do it again.

0:22:18.380000 --> 0:22:22.860000
 All right, so in packet tracer
 we created four pangs.

0:22:22.860000 --> 0:22:30.340000
 So if we go back to here, now we can
 see those numbers have increased.

0:22:30.340000 --> 0:22:35.020000
 Eight packets input,
 seven packets output.

0:22:35.020000 --> 0:22:39.560000
 And if we compare that against
 our sub interface of dot two.

0:22:39.560000 --> 0:22:51.360000
 Now in this particular case, it looks
 like the packet counters of input

0:22:51.360000 --> 0:22:57.600000
 and output are only being shown on
 the physical interface, not the sub

0:22:57.600000 --> 0:23:03.180000
 interface. Let me just check real quick
 and see if that's a packet tracer

0:23:03.180000 --> 0:23:06.580000
 thing or if real routers actually
 do the same type of thing.

0:23:06.580000 --> 0:23:09.080000
 I'm going to go into a real
 router here real quick.

0:23:09.080000 --> 0:23:14.720000
 You can tell by looking at my running config
 that I have created sub interfaces

0:23:14.720000 --> 0:23:17.040000
 on this router as well.

0:23:17.040000 --> 0:23:22.460000
 See, I've got a couple of sub interfaces
 tied to my main interface.

0:23:22.460000 --> 0:23:32.320000
 Now what I want to know is show it looks
 like you don't really have any

0:23:32.320000 --> 0:23:37.420000
 counters on your sub interfaces to be
 able to verify that one sub interface

0:23:37.420000 --> 0:23:40.860000
 is received a certain amount of packets
 versus another sub interface.

0:23:40.860000 --> 0:23:45.080000
 It looks like all the packet counters
 are actually associated to the main

0:23:45.080000 --> 0:23:46.640000
 physical interface.

0:23:46.640000 --> 0:23:50.440000
 So that's basically how
 you would monitor it.

0:23:50.440000 --> 0:23:54.260000
 You just number one, see if you can
 ping something outside your VLAN.

0:23:54.260000 --> 0:24:00.220000
 If you can reach outside your VLAN, you
 know the interface VLAN interface

0:24:00.220000 --> 0:24:05.380000
 interface inter VLAN routing is working
 between the sub interfaces that

0:24:05.380000 --> 0:24:07.220000
 you've created on your router.

0:24:07.220000 --> 0:24:10.240000
 Thank you for watching this video and
 I hope this one was useful to you.