WEBVTT

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 Hello and welcome to this video titled
 components of computer networks

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 Wi-Fi and DNA center.

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 In this video I'm going to talk about
 some common Wi-Fi components you'll

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 find in most computer networks today
 and I'm also going to give you an

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 introduction to Cisco DNA center.

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 Alright so what if
 I'm doing Wi-Fi?

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 You know what if I have my laptop, my
 smartphone, my tablet is not connected

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 to any physical wire but somehow magically
 I'm still on the network.

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 I can still surf Google or get
 on Facebook or whatever.

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 Well that's because you have a wireless
 mic, we just talked about that.

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 It's got an antenna, even if you don't
 see it, you've got an antenna,

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 it might be built in as part of your
 screen on the side or something but

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 you've got an antenna in there.

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 You've got a transceiver which is basically
 a radio capable of radiating

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 radio frequencies and receiving radio
 frequencies and what's on the other

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 side of that? What's picking
 up those radio frequencies?

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 It's one of these, what's called an access
 point or a Wi-Fi access point.

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 So in the case of a Wi-Fi access point,
 what you have here is you've got

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 multiple clients each with their own antenna,
 alright maybe this is smartphone

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 right here with his antenna and they're
 all connected to this access point.

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 They're not physically connected,
 there's no wire connecting them.

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 But when one of these guys first gets
 on the network, first thing he does

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 is he says, okay is there a Wi-Fi
 network around here somewhere?

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 And the Wi-Fi client, let's just take
 your smartphone as an example.

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 When wireless or Wi-Fi is turned on to
 your smartphone, it's always listening.

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 It's always listening to see if there's
 any Wi-Fi networks around and

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 you'd be surprised at the number
 of Wi-Fi networks it picks up.

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 Right where your standing I might say,
 okay there's a Wi-Fi network here

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 which is called John's house.

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 Well I'm John, I'm in my house.

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 Oh I'm also hearing a Wi-Fi network
 called Bogart's house, oh that must

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 be Keith Bogart's house,
 I'm getting his Wi-Fi.

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 I'm also getting a Wi-Fi network called
 Starbucks all within hearing distance.

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 So the next thing your Wi-Fi client would
 have to do is associate to that

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 network which means it would actually
 send a Wi-Fi frame to the access

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 point that is broadcasting
 that network.

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 So somewhere there's one or more access
 points are saying hey I own the

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 Starbucks network connect to me or
 I own the Jones network connect to

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 me. So if a client wants to connect
 to that network it's going to send

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 a Wi-Fi frame to the access point saying
 can I get in, can I connect to

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 you. And there's going to be a series
 of steps that are involved but once

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 the Wi-Fi client has associated to the
 access point now they can actually

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 exchange data wirelessly.

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 But you got to have an access
 point to make all that happen.

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 Now back in the old days when access
 points first came out we had what

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 were called autonomous or
 standalone access points.

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 So when you got the access point and
 you took it out of the box and you

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 plugged it in one of the first things
 you would do is on your laptop you'd

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 have to connect to it would have like
 its own little web page built in,

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 its own little graphical
 user interface.

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 You would have to connect to the web page
 of the access point and configure

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 it. You'd have to say okay I want the
 Wi-Fi access point to advertise

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 my home network, Jones
 Home or Sally Home.

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 And I want the access point to have
 these characteristics the network

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 is going to be this fast, it's going
 to have this kind of security and

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 you'd configure all of that
 on the access point.

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 And then when you were done you would
 stick it on your desk, stick it

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 in the wall or the ceiling.

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 The access point would actually have to
 have a network cable which connected

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 back to a wirelessly and then your
 wireless data from the access point

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 would be put onto the cable and sent
 back into the wired network.

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 Now that was all well and good when we
 had just one or two or three access

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 points but imagine for a moment a company
 that has dozens or hundreds

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 of access points.

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 It can get real tedious programming each
 and every one individually sticking

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 on the ceiling and then what happens
 if six months later you need to make

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 a change that's common across
 all the access points.

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 Are you going to rip each one down
 from the ceiling, connect to their

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 command line or the graphical user interface,
 their webpage and reconfigure

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 it? Probably don't
 want to do that.

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 So some people came around and
 they said you know what?

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 It'd be a much more scalable situation
 if we had some networking device

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 that could control all
 of my access points.

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 So rather than logging into each access
 point one at a time autonomously

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 as a standalone access point, I'll
 just go to this other device right

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 here. I'll program him.

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 The access points will reach out to
 that device and when they connect

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 to that device they'll find out how
 they should be programmed and that

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 is what we call a wireless
 controller.

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 So wireless controller is a box that
 controls multiple access points.

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 It's a much more scalable solution,
 a central point of management for

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 groups of access points.

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 It can also control Wi-Fi
 access for the clients.

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 You see with an autonomous or a standalone
 access point when a client

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 like your tablet, your smartphone says
 hey, access point, I want to connect

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 to you. The access point will say okay
 sure here's the security we use.

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 The client will send across
 his credentials.

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 Hey here's my username
 and password.

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 So that security exchange about hmm
 should I let that guy on the Wi-Fi

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 network or not? Does he have
 the right credentials?

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 That will be a decision that the access
 point himself will have to do

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 which means in an autonomous or standalone
 access point you would have

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 to configure it to do that.

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 Well with Wi-Fi controllers you can
 go to the controllers and you can

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 say hey controller I'm going to configure
 you and now whether two access

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 points or fifty access points connect
 to the controller all the access

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 points can be told hey all you access
 points here's the type of security

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 we're going to use.

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 Here's you know when somebody connects
 to you pass them through to me

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 the controller and I'll authenticate
 them and make sure they're allowed

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 on or not. So what some differences
 between controllers because there's

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 a lot of different companies out there that
 make them a lot of differentiators.

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 Well one thing is the quantity
 of clients they support.

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 Some of the higher end controllers can
 literally support tens of thousands

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 of Wi-Fi clients all
 at the same time.

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 The features available you know do
 they have security features do they

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 have other types of
 features built in.

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 Are the appliance or cloud based like
 what we see here this graphic is

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 an example of an appliance.

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 An appliance in networking terms is
 a physical box that you can hold you

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 need to plug it in this design to do
 a specific task that would be an

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 appliance like okay for example your
 microwave is an appliance right it's

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 a physical box. It's designed to heat up
 your soup or heat up your hamburgers

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 that appliance is different than your
 refrigerator right they're both

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 physical things you can touch and feel
 but their purpose is different.

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 Same thing here in the world of networking
 when we say oh I've got a network

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 appliance it's a physical device that's
 designed to do a specific task

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 so controllers you can buy them and
 install them in your own company as

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 an appliance or you could do
 a cloud based situation.

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 Where you say you know what the controller
 I'm not actually going to see

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 it I don't know what it looks like it's
 in the cloud it's reachable via

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 the internet so I'm going to reach out
 to Cisco or Meraki or some other

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 company and I'm going to pay them maybe
 a yearly subscription once I pay

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 them now all the access points in my
 company can reach out through the

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 internet and contact
 their controller.

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 I still have access to that controller
 so it still has a web based GUI

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 but the controller is not physically
 in front of me I can access that

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 GUI I can manage it I can control it
 but it's in the cloud it's reachable

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 via the internet and the types and quantities
 of uplink interfaces a controller

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 is also going to have physical nicks
 physical connections to wires how

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 many nicks does it have how fast are those
 nicks what kind of wires connect

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 to that controller those
 are all differentiators.

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 Okay so so the last component I want
 to talk about here so I just sort

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 of gave you the example of we start out
 with access points being standalone

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 or autonomous each access point managed
 configured individually and then

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 we said okay not really scalable if I'm
 going to have any more than about

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 five of these things I like to have one
 central device called a controller

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 which manages and configures all of
 my access points okay let's take it

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 up a notch imagine you've got a network
 this got 500 switches we've talked

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 about that maybe another 500 routers
 maybe another thousand access points

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 wouldn't it be nice if there was some
 central point of management for

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 all of that stuff some central thing
 I could log into it gave me a nice

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 web based graphical user interface
 that showed me in that one pane of

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 glass they call that a single pane of
 glass because I'm just looking at

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 this one website and through that I
 could see a listing of every single

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 device I have on my network I could
 configure all those devices I could

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 change them based on what my needs were
 wouldn't that be cool well Cisco

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 has come up with something that does
 just that which is called Cisco DNA

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 Center DNA in this case standing for
 the digital network architecture

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 so like it says here Cisco DNA Center
 is a centralized management dashboard

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 not just for a bunch of access points
 but for complete control of your

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 entire network this is going to blow
 your mind here so just think about

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 this for a second provides a central
 automation and analytics platform

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 to facilitate intent based networking
 what the heck is that talk about

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 marketing speak so what this is really
 talking about is you know up until

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 recently when people were designing
 a network their primary thought was

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 okay hmm how many devices if I so imagine
 you have an empty building okay

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 and your job to figure out what cables
 are going to go through that building

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 how many routers how what makes and
 models of hardware you're going to

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 buy and purchase so these are traditionally
 what you would think about

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 is okay how many hosts am I going to have
 in that building how many laptops

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 PCs network based printers IP phones
 okay I got to think about that what

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 type of data are these hosts going
 to be doing is it just going to be

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 web browsing is it going to be doing
 other stuff like I don't know sharing

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 of music files you know what are they
 going to be doing and where are

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 they going to be located throughout my
 building are they going to be clusters

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 they can be sort of evenly interspersed
 out am I going to need just wired

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 or combination of wired and wireless
 so all of that stuff would help you

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 design your network till you got to
 the point where you sat back like

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 six months later and said whoo cyber
 leave access points are all in place

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 wires are all done routers and switches
 are in place everything's chugging

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 along great now what happens if a year
 later somebody introduces a whole

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 new application and the network you've
 got isn't really designed for that

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 application it's not really working
 as good as it could this is where

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 intent based networking comes in intent
 based networking says okay my

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 network infrastructure is already out
 there okay I've got my wires and

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 my physical devices all plugged in
 intent based networking says based

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 on what my intent is right now the intent
 of what applications do I want

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 to use how do I want the network to react
 to those applications do I want

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 the network to dynamically adjust throughout
 the day based on what applications

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 are running which ones are not that's
 my intent and I can use something

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 like DNA center to make my intent a
 reality I can go into DNA center and

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 say okay let's you know let's we can't
 change the physical nature of the

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 network I can't make a router just vanish
 and disappear or make a switch

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 there it is it didn't exist before I
 can't do that but with intent based

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 network I can say hey let's dynamically
 adjust the network and optimize

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 it so so it's better for this application
 over here that just came online

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 maybe and penalizes other application
 over here let's let's push down

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 some new wireless policies that didn't
 exist before that is intent based

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 networking taking your intent of what
 you want the network to do which

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 can change from day to day month to
 month year to year and making that

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 a reality by pushing down new configuration
 commands and stuff and that's

0:12:52.860000 --> 0:12:59.180000
 what DNA center is all about so DNA
 center is an appliance remember we

0:12:59.180000 --> 0:13:03.000000
 said what an appliance is it's a physical
 box you can touch and feel that

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 you plug in somewhere that has special
 software in it called DNA center

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 software and we call this controller
 they say but Keith you just talked

0:13:13.160000 --> 0:13:17.200000
 to me about a wireless controller yes
 but a wireless controller the only

0:13:17.200000 --> 0:13:22.180000
 thing that it controlled were access
 points and that was it the DNA center

0:13:22.180000 --> 0:13:27.580000
 controller can control access points
 routers switches even servers out

0:13:27.580000 --> 0:13:33.180000
 there it can control everything almost
 connected to the network central

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 point of GUI based network control that
 allows you to design your network

0:13:36.960000 --> 0:13:40.120000
 so one of the things that DNA center
 has in it is before you even lay

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 down a single cable or purchase a single
 switch it's got this little section

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 of the GUI where you can sort of design
 a network you can say okay what

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 if I plug in or switch in a router
 here and I connect them up and see

0:13:50.360000 --> 0:13:53.180000
 how's that look do I think that's going
 to work for me instead of doing

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 it on a piece of paper with chicken
 scratch and a pencil you can do it

0:13:56.180000 --> 0:14:01.880000
 within DNA center you can create topology
 maps and diagrams you can identify

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 golden images for software deployments
 a golden images basically a term

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 of you know let's take a network based
 switch for example a network based

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 switch might have lots of different
 versions of software that can go on

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 it like your laptop right with your
 laptop technically there's windows

0:14:17.200000 --> 0:14:23.400000
 95 windows 7 windows XP windows 10 okay
 well at some point if you're in

0:14:23.400000 --> 0:14:27.620000
 charge of like 50 laptops you're gonna
 say you know what for our organization

0:14:27.620000 --> 0:14:32.400000
 we're gonna standardize with windows
 10 that's our golden image that's

0:14:32.400000 --> 0:14:35.460000
 one the one we're gonna put on everything
 we've tested it we know it works

0:14:35.460000 --> 0:14:38.740000
 it doesn't have any bugs that's the
 one we want so that's what we mean

0:14:38.740000 --> 0:14:41.700000
 here by a golden image is we can say
 for our routers and our switches

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 and our access points here's the certain
 flavor of software we want all

0:14:46.420000 --> 0:14:51.660000
 these devices to consistently run we
 can even control our wireless stuff

0:14:51.660000 --> 0:14:57.240000
 by creating wireless profiles and SSID's
 and this has a GUI based configuration

0:14:57.240000 --> 0:15:01.100000
 of network devices so there's a lot
 of stuff on this slide right here

0:15:01.100000 --> 0:15:03.740000
 you probably don't need to know the
 main thing is I want you to look in

0:15:03.740000 --> 0:15:07.560000
 the upper left hand corner you can
 physically see there the different

0:15:07.560000 --> 0:15:11.700000
 flavors of the DNA center appliances
 that you can purchase and you can

0:15:11.700000 --> 0:15:15.460000
 see it varies based clearly on its size
 how much rack space is going to

0:15:15.460000 --> 0:15:20.960000
 take up as well as how many devices
 it can control you know routers and

0:15:20.960000 --> 0:15:25.300000
 switches and access points oh my lots
 of things to think and control and

0:15:25.300000 --> 0:15:29.020000
 there's a lot of other stuff in here
 that is way beyond the scope of this

0:15:29.020000 --> 0:15:34.580000
 video so that's been a lot of stuff
 I know but that finishes out this

0:15:34.580000 --> 0:15:39.720000
 video on network based components I
 hope you found it useful thank you