All language subtitles for 10 - Switching - Working with the Cisco IOS-eng

>> Working with the Cisco IOS.

Can I side tangent?

[laughs] I know you're like,
you can't side tangent

until you have something to side tangent from.

You haven't even started.

I know, I know but I just have this thought
and I-- the topic is kind of around the--

you know I always get the question, people are
saying, well, how do I get into the Cisco career

or how do I open doors or how do I-- you
know, how do I be successful in this career?

So I have this thought in my-- I think
I've got an answer to that in a nutshell.

So-- so today is November 27th, 2012.

It is kind of the Christmas season in Arizona.

It's, you know, 63 degrees outside,
freezing temperature and I'm sick.

It always happens, and nothing like flu.

It's just the stuffy head and your nose,
congestion, scratchy throat, you know, coughing.

You know I'm like a NyQuil
commercial waiting to happen.

And so-- and you know this morning I wake
up I'm like-- I'm not recording, no way.

You know I'm not feeling well.

I'm just going to make some
slides, you know, create--

maybe create some labs, going to
do some-- some flow of the course.

So about 15 minutes ago, I'm walking out in the
kitchen making some tea and my wife goes "Wow,

you must be rough, you know,
you don't even like tea,"

and then I'm like, "I know,
I'm going to record."

What? What?

What? I thought you're not-- and I know, I know.

I just finished the slide for working with the
Cisco IOS and I'm so excited to talk about it,

I can't even focus on what's coming next.

I can't-- and you know like I'm looking at the
blank white screen and I'm like I can't even--

I can't even do stuff on it because I'm
thinking so much about things I want

to say and this day I got to record.

So now here I am.

I got my cup of tea, it's hot,
and it's helping me record this

and so you're going okay, what's your point?

You know we've established Jeremy's
kind of odd, a little freaky.

What's the point?

Okay, so here's my point.

This is now 15 years of training for me
which is weird to be able to say that

and I've gone through a lot of technology.

I didn't start in Cisco.

I started in Microsoft and Novell and then
actually even before that, in college,

computer programming, computer science
was my degree and I hated them.

You know, I hated computer
programming when I was in college.

I was like-- so much so that I got out of
college and I went to Pizza Hut because I was

so convinced that I didn't like computers
that I was like, "I'm going to work

in the pizza industry and further myself there,"
and then I realized I didn't like pizza either.

So nonetheless every technology that I've
run into always when I start into it,

I'm frustrated, I don't get it, I read it
and I'm like I don't get it and I listen

to it again, I'm like I still don't get it.

You know and I reach these points from the--
you reach these decision points where like okay,

I either push through this frustration until
I really get it and maybe it's listening

to a nugget again, reading it from a
different book, Googling a different source,

posting to a forum and helping somebody unders--

you know, explain it to you or
talking to a friend, whatever.

You reach a point where you either say, "I'm
going to push through until I get this,"

or I'm just going to be like, "Ah,
whatever, I'll move on to the next thing."

The more of those, "ah, whatever" moments you
have, the less passion you will have towards

that technology, you might say-- you
might [inaudible] why do you care?

Well, because the more passion you develop
for something, the better and better

and better you're going to get
at it to the point to, you know,

now I'm like, "Well, how do I get a career?"

To the point where somebody
will be crazy not to hire you.

I mean I've-- I now own a company.

I've interviewed people to where, you know,
that some people will come in and they're like,

"Yeah, I've gotten some experience
in this field."

I'm like so, you know, describe a DHCP server
and they'll-- you know textbook and well,

a DHCP server is a server that hands
out IP addresses to clients and--

you know and then I'm like, okay, you got
the right answer but where are you at?

[laughs] You know, I'm like you are--
like are you excited to work here?

Are you-- are you excited about this technology?

And then, you know talk to another guy
who's like, "Oh man, oh man, I just--

I just finished my course at, you know, the
community college or whatever and then like--

and oh man, and I think I-- you
know, I haven't even done this

yet but I really have a good idea.

You know based on what you've told
me that we can design it this way."

And you know I'm like, "Bro, you
are on board," because I know--

I know, you know, one person is going to be
looking at, "Okay, well, it's about 5 o'clock

in the afternoon, I'm done, you know.

All right, see you, see you for today."

And then I've got another guy who's like,
"Man, it's 5 o'clock, I'm going home,

spend a little time with my family and then 10
o'clock I'm waking back up or I'm jumping back

in and I'm going to, you know, finish
this network diagram or whatever."

So when it's like, "Well, how
do I open doors in Cisco?"

I know it's kind of like
well, it's the generic answer

but there's no replacing just a genuine
goodness, you know, to where you're just good

at the technology and you're
really excited about it

and you can apply that principle to anything.

You know, I'm talking technology now but,
you know, take your marriage, you know.

You know, I am not wife certified
but if I spend--

the more time I spend trying to figure out my
wife, the better and better the marriage get

or your kids or, you know, fill in, you
know, life circumstance and the more--

you know every life circumstance is
frustrating and you have that decision.

Do I walk away and just be like,
"I don't get it," you know.

Or do I really push through and
become a master of that technology?

Anyway, that's how you're
successful in this career.

I know it's not a-- well, you know, call
this guy and he'll get you in but that will--

I guarantee you, that will open doors.

So, working with the Cisco IOS, this
is-- and you know, what a great intro.

I'm almost, you know, I'm so excited.

I'm kind of like shaking.

I'm like how do I even get
into the IOS in transition?

What a good intro into the foundation
software of everything Cisco.

So imagine for a moment that you
had never seen Microsoft Windows.

You know this-- that we would have to have an
introduction saying, okay, well this is Windows,

this is a task bar, this is
how you minimize and maximize

and open a program, all those kind of things.

This is what that is for Cisco, you know,
essentially IOS is the Cisco operating system.

So we're going to go through
and get familiar with it.

Well, let's start off with
defining the Cisco IOS.

IOS stands for Internetwork Operating System.

It is the operating system that has
become the standard in the world today.

Now, you might look at for instance let's
take Windows and then let's take Linux

or McIntosh OS X. So Windows right now, you
know I'm talking end of 2012, things may change

but Windows has a 93 percent market
share in businesses in America.

You know now-- now Apple and McIntosh
is kind of creating this ripple effect

to where they're like, "Oh, you're-- you've
got to get on OS X," and you're like, "Oh,

but the fact remains OS X
today still only has a five

to six percent market share
in businesses in America."

Why? Well, because McIntosh,
while amazingly cool,

I love the McIntosh operating
system, nobody knows it.

It's kind of like you are really hitting a
learning curve if you are familiar with Windows

and then you come over to McIntosh and you're
like, you know, "Where is my IP config?"

Well, I guess I'm talking techie,
you know, like "Where is my programs?

How do I get there?

How come when I save this file, it's not
compatible when I e-mail it to that guy?"

I mean like all of those things hit people
and frustration escalates really fast.

Now Cisco has created the IOS which is a command
line operating system that is very well known

in the industry as in if you learn-- you
know there's a lot of vendors out there.

Let me-- either Cisco, there's-- let's just say
Foundry which actually is now bought by Brocade.

There is-- well, I'm just drawing
out some vendors, 3Com, HP.

I think those two merged and whatever.

The politics of companies beside there's a
lot of people who create networking stuff.

I'll even throw Juniper in-- into that mix.

Now, this is the only nugget where we
will mention these kinds of companies

and then you are banned from
mentioning them in the future.

But there're all kinds of
companies out there and all of them

when they create their operating system
for interfacing with their device,

you will find for the most part, it
is very similar to the Cisco IOS.

Why? Well, in the same sense that Linux,
you know or McIntosh, you know people know

if they just go way off and start creating
their own world that people are going to walk in

and it's too radical of a change to where
no matter how cool the operating system is

or how cool the feature is, people
are going to immediately like, "Whoa,

I'm not going to go there
unless there's a very"--

I mean unless you create a feature that is so
cool and so irreplicable that people are like--

they're coming to you because of that feature.

I mean people aren't going to go there.

So learning how to work with the IOS is huge,
not only for working with Cisco but for working

with any networking equipments in the industry.

So this software, and that's the look and feel.

You kind of see a view of it there that's
kind of-- that's what the IOS looks like.

It's consistent through nearly
all Cisco devices.

Now I say nearly all because
Cisco has other stuff

like for instance Cisco ASA
Firewalls would be one.

They cannot use the IOS on there 'cause
that would be a security vulnerability.

If they found a security hole in the IOS,
then it would also be true of their firewall.

So they created their own
operating system through the ASA

which you will find them described as IOS like
to where it's like the IOS, it feels like it

but there're some differences that are in there.

Same thing, you know, as you
get into Nexus equipment.

I mean there're different families but they
all kind of have that same look and feel.

Cisco's goal is that you learn it
once and then use it many times.

So Cisco knows that the hardware that
you buy can be replicated by anyone.

Everybody buys the same chips, same-- now
of course you could say well, you know,

there's certain vendors that say well, okay, but
hardware wise, people can all buy the same stuff

within a couple of years of each other.

So Cisco really differentiates
itself through its software

and Cisco will describe themselves much
counter and counter to most people's belief,

they will say, "We are a software company.

We are not-- our primary focus is not producing
hardware 'cause hardware can be produced

by anyone."

Now the IOS and learning the command line
is more powerful than any graphic interface,

which is tough when you're first getting
started 'cause it's a learning curve especially

if you come from a graphic interface background
and you're not used to typing in commands

to do this kind of configuration.

It's tough to move away from that world but
once you learn it, you're kind of like, wow.

You know, you reach the point where-- even if
you have a point and click GUI for instance,

there are things now-- Cisco has
the SDM GUI to manage devices.

That can accomplish almost--
well, most major things.

But I just don't use it at all
not because it's a bad interface

but because I find myself facing a learning
curve again to where I'm like, okay,

I know if I'm in the command line I would type
config T, interface that, do this, do this,

do this and I'm done, whereas here
I'm going, "Where is that again?

You know, is it in this Window?

No, no, okay."

So you know, people will obviously
gravitate to whatever they know.

To learn the Cisco IOS, there's no replacing
seeing it and doing it and actually interacting

with the operating system itself.

So that's what we're going to do for the rest
of the nugget, it's just kind of work in there.

So this is a review slide.

This is what the whole last nugget was
about, so I won't go through it all again

but in essence this is what I've done.

Grabbed the console cable, plugged it into
the serial port of my PC, grabbed that end,

connect it to the console port of the
switch, booted up my terminal program

which I'm actually using Tera Term, but any one
of those will do, and then set the serial port

to the settings and now we're good.

Now I'm actually using Tera Term,
which is my nice black window.

And I reach down here and
plug in-- plug in the switch.

Couple items of notes, switches, while
we're waiting for this guy to boot,

switches don't usually have power switches.

Essentially if you plug it in, it is on and
working, whereas routers on the other hand,

usually do have power switches so you
can turn them on and off and that kind

of thing without disconnecting the power.

Also, I'm using right now a Cisco Catalyst
3550 Switch which is a phenomenal lab switch.

You can get them now fairly inexpensive

because this switches a layer
two and a layer three switch.

Now, we'll talk about layer three
switching a little bit later.

It's actually not officially part of this series
but it's so valuable that I want to bring it

in 'cause you're going to
run into it everywhere.

And so, it can do routing
and switching together.

So, what a great device.

So right now, what's happening is let's just
think of this as its power on self test,

you know, just like your computer
where it's like checking memory.

We saw this in the last nugget, it's
taking that IOS, that's the image,

there is your file name right there
and it's copying it over to memory.

It's decompressing that guy from flash into RAM.

Now once that process completes,
then it's going to go through

and actually start running the IOS.

It's going to look for any
configuration file that it has.

If-- you know, to see if this device
has been previously configured,

and if so we'll apply that.

But eventually it's going to end at either--

either number one, a prompt where you can just
start typing in commands or it's going to end

in a question that will say, "Do you
want to enter initial config dialogue?"

That question, first off I will say
means you have no configuration,

like this device has been erased or it's brand
new and it's never been configured before.

Second thing I'll say about that is when
you see that question, always answer no.

Now a little side note as this comes up.

This is the model number of the switch I
have, and it's actually a 24-port power, PWR.

That means it's inline power, as in if I
plug-in IP phones or wireless access points

or video camera, they can
actually get their power,

their electricity from the
Ethernet cable on this device.

It's really, really cool.

Now, here's-- this is great.

So here's the question, I said you
always want answer no to that question

and all of a sudden you see [inaudible]
like whoa, what just happened there?

What those are are status messages or
some people will call them syslog messages

that are coming through letting you know, "Hey,

these are things that are happening
in your software right now."

It's kind of like a log file.

Now, if you're not used to those, well, I'll say
get used to those, they'll happen all the time,

but initially they may frustrate you.

They may be like well, you know,
I'm supposed to be typing up here

but my cursor is blinking
right here, what do I do?

Well, usually if you hit the tab
key, now it's not going to work

at this point 'cause it's asking me
a question, but hitting the tab key

on the keyboard will repaint
whatever you were typing.

So if this cut what you were typing in half,
hitting the tab key will fix that for you,

and I'll explain that more later.

But for now I'm just going to hit the enter
key 'cause I know it's going to keep asking me

that question until I either say yes or no.

So I'll type in no, always
answer no in that case.

No. You might be thinking, what is that?

What if I would answer yes?

Well, what that is, is kind of an initial setup
wizard that Cisco has created from moons ago.

I mean it's going to walk you
through configuring protocols

that just don't exist anymore, things
that we just don't use anymore.

It will walk you through
configuring like IPX/XPX, AppleTalk,

I mean things that just aren't
normal for us to use.

Instead, we want to configure
the switch or router, you know,

'cause they both use these same
commands and same configuration.

Configure the switch or the router manually
using the different modes that are there,

and that's the big-- the big
topics that I want to talk about.

So, these are the modes of
configuration of Cisco IOS.

But before we even dive into that, let
me go back to the-- back to the switch.

My window closed.

So I'm back in the switch so this is, you
know, after I've hit enter a couple of times,

it comes up to this prompt
which is considered user mode.

In user mode, you can do some limited commands.

You can work with the switch, you know,
and view some of the configuration

but you can't even view all of it, it's just--

it's a very limited mode for just basic
reconnaissance like let's see what's going on.

So before we start navigating to the
different modes, let's get familiar, okay.

I'm sitting here, what do I type?

How do I type it?

Well that-- that leads me to
I would say the biggest thing

that made Cisco famous is their help system.

At any point, no matter where you are in the
configuration, you can hit the question mark

on the keyboard and it will give you a list
of the commands that you're able to type in.

So I'll go, okay, well I'm
in user mode, what do I do?

I hit question mark, I'm like, oh, well
these are all things that I'm able to do.

Oh, look, I can ping something.

I can make sure that it's online
or I can-- I can show something.

I can view some kind of configuration from this
device or I can SSH-- start an SSH session to--

I mean these are all things
we haven't talked about yet

but these are the commands
that you're able to do.

Now you might say, okay, well-- okay,
maybe I want to ping something so I type

in ping and I go, okay, is that it?

Well, at anytime you can do ping and
then do, you know, space question mark

and it will give you the
commands that relate to ping.

So let's say, okay, well you
can either type in a word.

Now anytime and here's-- here's a good rule for
you, anytime you see something in all capitals

in the help menu, that means it's a
variable, like type something in there.

You don't actually type in word in all capitals,
they're saying what do you want to put in?

You ping the destination address or host name.

So maybe I want to say ping
4.2.2.2 as an IP address

or ping google.com, you know,
would be something.

So it's saying, you know,
we can type anything there.

Or it says you can either type
an IP, which would be fine.

I can type in ping IP and I go,
okay, well what comes after that?

Hit the question mark and it says, okay,

well type in whatever address
you want to type in now.

Now you might say, "Well, couldn't I
have done that by just typing it here?

I mean do I have to type an IP as well?"

Well no, sometimes there will be multiple
ways of accomplishing the same thing

in the Cisco IOS and this is an example.

Ping and then IP address or name is the same
thing as ping IP in the IP address or the name.

But notice you can also go different directions.

I could say ping IPv6 and then
it says, okay, well, what IPv6--

that's TCP/IP version 6,
the next version of TCP/IP.

What TCP/IP version 6 address
do you want to ping?

Or, you know, the list goes on and on.

So, let me first off say, there is no
shame in using the question mark at all,

whether you're in production or
even on the certification exam.

You will have simulations where the
question mark is absolutely valid and a lot

of times Cisco wants you to go that
direction because there are literally millions

of combinations of commands in the Cisco IOS.

Don't let that discourage you, let that
encourage you because you have a question mark

that will really walk you through it.

You know in Windows-- in Windows
if you are doing something,

most of the time they have a Wizard, right?

You open it up, it's like, okay,
you're going to install this program.

What-- where do you want to install?

You put in C colon backslash program
files and then you hit next, right?

And then, oh, what options do you want?

Next. And then, you know, whatever,
you know it's kind of like next, next.

Your people say it all the time, next,
next, next, next, finish and you're done.

Well, think of the question mark as
your next command to where you're going.

Okay, well I want to, you know, now this is,
you know, I want to do something with Crypto,

you know, the encryption-related commands up
there and I go, well, you know, what do I do?

Well, here's your next button, I just hit next.

It says, okay, well I need to type in key,
you know, there's not much else I can do here.

Next. And then it says, okay,
well do you want that in?

So, it's asking me these options.

Now obviously, you have to know
why you're doing something.

You can't just say, "Well, I want to do
something with encryption and do that."

You have to know what this command
is for or why you're doing it

but you always have a question mark or
a next button to walk you through it.

Now, also right along with this is the tab key.

Now I mentioned that the tab key can
kind of repaint what you're typing

if you ever get interrupted by
those messages, which is true,

but it will also finish any
partially typed command.

So let's just look at this.

I see-- I see two commands that start with
D. Actually I forgot to show you something.

I can type in D question mark.

Notice no space at all and the IOS is like,
"Oh, you just want to know what command start

with D," and it will filter
down to just those two.

Now I'm going to hit the tab key, watch this.

What just happened there?

It just said, okay, he hit tab which--

which really means finish the
command that I've started typing.

But now the Cisco IOS is saying, "Well, both of
my D-Command start with DIS, so I can finish it

that far but now I don't know
which direction you want to go.

Do you want to disable or
do you want to disconnect?"

So, as soon as I type in that fourth
character, let's say I put a C there,

it now knows I want to disconnect.

So I can hit the tab key and
it finishes that command.

You will start seeing people that
have a lot of experience in Cisco

that that tab key is like their best friend.

They're just constantly, you know, they're--
I'm just going to type a few things real quick,

you know, copy, running config
to start up config--

I mean it just becomes like second nature
to you in the commands that you're doing

to just say, okay, let me hit that tab key.

Now-- now let me also mention this.

Ignore the commands I'm typing, I'm just kind
of showing you how to work with this here.

I'm going to do a disable,
take me back to that user mode.

What was I going to say?

The tab key is also optional.

So let's say I want to-- well,
let me get-- let me get back here.

I want to disable, right?

Well I know, you know, I'm going to type in
DIS which it's still saying, okay, wait a sec.

There're still two commands I don't
know, but now as soon as I type in A,

does it know which command I want to use?

Yeah, it does because disconnect
doesn't have an A there.

So, if I just hit the enter key
there, it executes that command.

Okay, rule across all Cisco IOS.

You can use a shortcut of any command
as long as you type enough characters

for it to be uniquely recognized.

Okay, so for example one of the big
commands you will always type is enable.

Enable is actually the command.

Where's my pen?

Enable is the command that allows you to
move from user mode up to privileged mode.

That's one of the first commands
that we're going to discuss.

You will find almost-- hardly anybody
actually types in the enable command.

Almost everybody will just get in, they will go
EN because that's the shortest version of enable

that they can type and still
allowed to be valid.

Or, you know, disable is actually
a command that's rarely used

but disable moves you back to user mode.

It's kind of like why would I ever
want to deescalate my privileges?

I want to always escalate, you know.

Anyway, well, maybe you do.

Well, you know, what if you
don't want to leave it logged in?

Well, most people will just type in
exit, you know, and drop back out.

So they're now back in the-- back in that mode.

So, any command can be shortcutted
that way, okay.

So, now let's talk about the modes themselves.

Knowing the modes of your Cisco
devices is almost as important

as knowing the commands themselves.

Actually, let me change this thing and I'm
going to revise my statement right there.

Knowing the modes of your Cisco device is
more important than knowing what commands

to type themselves, that's a bold statement.

Think of it this way.

Have you ever-- you guys remember the game Myst?

Oh, I despise that game.

It was when computer graphics where it's first
starting to get really good and essentially

with Myst, you would be put in all these
different puzzle scenarios like you would walk

into a room and you know in this room, all these
different gadgets do things like if I click

on that part of the screen which you know
spins the little timer and then I click

on the notebook to open it up and look inside of
the notebook, then I'm going to find the piece

of paper that only appears
if the timer is spinning.

Where if I chose to do it
when the moons were aligned,

I would then progress to the next level of Myst.

It was one of those kinds of games
where you just spend hours staring

at the same screen trying to figure
out what area of the screen to click

on at what time to make something happen.

Well, in the same way, think of these modes
of the Cisco IOS like the areas of the screen.

When I'm in user mode, I have a
certain set of commands that I can type

in that-- and you saw them matter of fact.

When you first get into switch, this little
right angle bracket right there lets you know

I'm in user mode and I hit the question mark
and, okay, you get a feel that that's it

by the way, that's all the
commands you can type in.

Oh, actually sometimes-- forgive me,

sometimes I've been doing this
long enough that I assume things.

When you see a more, you can either scroll line
by line by pressing the enter key like that

or you can scroll a page at a
time by pressing the spacebar

which in this case scrolls the rest of the way.

Now if you see a more, the enter key

and the spacebar is the only ones
that kind of move you around.

If you press any other key like sometimes
I'm like, okay, I've seen enough,

I'll hit the Q key, it just
stops the output right there.

Now, I hit Q but I could also go in
and hit M or any key except space

or the enter key will stop that up.

Okay, so you get the feel, right?

These are all the commands
that are in user mode.

Now, as soon as I type in enable,
I'm now moved into a privilege mode.

I know I am because I'm looking
at that pound symbol on my device.

That tells me I'm in privilege
mode which says I now have access

to all the functionality of this device.

There're no restrictions on what I
can do anymore, I'm now escalated.

Now, you might say well, what is--
you want a password protect that?

Well, absolutely, but this is
a device with no configuration

so there is no password yet, right?

So now watch what happens.

I hit the question mark and I go, okay,
well there's some and hit the spacebar.

Good grief, and there's some more and--

I mean, wow, can you see the difference
between user mode and privileged mode?

Again, going back to that Myst,
it's like one mode I'm in a room

with a couple little buttons
that I can push and look around.

In another room in Myst, I'm in this
gigantic galaxy where anything is possible

and remembering that each one of these
things, you know, when I type in show

and hit the question mark, each one of these has
a whole giant subset of commands that could go

in there and each one of those
to have a whole giant subset.

Again like I type in show IP and
you know hit the question mark,

it's like good grief, you know.

And like each time you do that, it's like
walking into a new room with Myst where you have

to kind of figure out what to do.

But the point is, the reason I said
knowing what mode to be in is more valuable

than knowing what command to type is because
given enough time, you can kind of poke

around in the mode and kind
of be like oh, okay, I see.

If I do this and this and, you know,
as long as you're in the right mode

to start off with, okay, that makes sense, okay.

Now don't let-- when you see that
gargantuous amount of commands, don't--

again, don't let that scare you away.

In your Cisco career, you will always only
know a subset of commands that there are--

like I said, there're millions of
combinations of commands in the Cisco IOS.

There are some core commands that will get you
going and then there's some peripheral commands

that those are the ones that
reference books are made for, you know,

you'll look them up when you need them.

So, two modes that we've talked about so far.

User mode allows limited visibility of the IOS.

You know I can do some-- this is meant for
a help desk technician to come in there

and say "Oh, look it's running," or "Oh,
look I can ping it from this device."

And that must mean that it's working or, "Ooh,

I can't ping it from this
device, so it must not be."

Once you move to privileged
mode, now you have full options.

This is where the admin, a
true Cisco admin is engaged.

Now in the privileged mode itself, you know,
we're sitting here from that pound symbol,

there's a lot of stuff that you can do.

I mean, there's a lot.

But from this-- from this mode itself,
you can't really configure anything.

This is all, you know, kind of working with the
IOS like you can do some ping commands you know

and go that way or you could go,
you know, do some show commands,

do a show running configuration and see, well,
here's how my device is configured and I can--

you know, you can kind of go through and
get a lot of information from the switch,

get all the information from the
switch but you can't change anything.

To change something, I have to start
moving into the configuration mode.

The configuration mode always starts with
global, meaning I move from user to privileged,

from privileged to global and then I can
either do some config there or move into one

of the hundreds of subconfiguration
modes that I have.

So let me give you an example.

I type in, and here's the command by the way.

To move in the global configuration
mode, I type in configure terminal.

In a nutshell that means I am
configuring my device from the terminal,

you know, that's why I'm doing that.

You can configure that device
from all kinds of sources.

I can copy configurations from other places or
do it remotely, you know, all that [inaudible]

but I am configuring it from my terminal.

That's the most common place
that you configure it from.

Now I've just moved, and you can
see the prompt changed to config.

I am now sitting in global configuration mode.

Things that I change here are
global to the whole device.

I mean things like the name of the
device, like I can type in host name,

you know this is a global option.

And by the way I'm just-- this nugget, I'm just
about the modes, I'm not about the commands.

I'm just using these commands to demonstrate the
mode, so I can type in host name Jeremy needs

to cough [laughs] and I'll be
pausing shortly to do that and you--

oh, man, I even went beyond that.

So, Jeremy needs to cough now
becomes the name of this device.

It's a global change that
affects the whole thing.

Or for example, sending a password to
protect this transition, setting a password

to keep people from going from
user mode to privileged mode just

by typing in a command is a global change.

So all of those kind of things,
and there's a lot

of them can be done from
global configuration mode.

But then from there, and I noticed this is
where I brought this little cheat sheet in here,

I can move into any one of
the subconfiguration modes.

So for example, this device, this
switch has a whole bunch of interfaces.

Hang with me for a second, I will show you.

And actually I'm going to-- I want to
show you something-- oh, perfect, perfect.

So, I've got this pound symbol, right?

And now my cursor is blinking
here, so I'm going to do a show--

whoa, wait a sec, that doesn't feel right.

You know, I'm typing my show command right
here but it's at the end of a status message.

What do I do?

Tab key, right?

Tab. Moves me down to the next line, gives me a
good prompt again and now I'm typing my command.

Okay, so I'm going to do
a show IP interface brief.

By the way, that's my all time favorite command
in all of Cisco, and I'm able to see all

of the interfaces that this device has.

Now-- and I'm going to stop saying
this, but we will discuss all of that.

You know, what does this mean, what's
the zero slash whatever, you know,

all of that to be discussed, just
talking about modes right now.

But let's just say I wanted to
configure just that interface.

That interface connects to a key
server and I want to make sure

that it's working the right way
or whatever the case may be.

So okay, I want to set up that
interface, here's what I do.

I'm going to go into global config, so
I'll type in config T. And by the way,

let me just show you that
again, I can type in cough.

Oh, I'm so-- I'm so into the
tab key I just hit it naturally.

Cough T and that will do the same thing,
that's a nice shortcut to do there.

And then I can say, well, I actually want-- I
don't want to do anything global to this device.

I want to just do that one interface, so I'll
type in interface FastEthernet0/1 and hit enter.

Notice every single time I'm
doing this, my prompt is changing.

Let's say okay-- okay, you've
now moved from kind of global--

there's a global sense configuration
mode into an interface.

So now all the commands that you type, you've
entered another room in that Myst video game,

all the commands that you type
affect just that interface.

So you'll see commands like I want to set
the speed of that interface to 100 or I want

to set the duplex of that
interface to full duplex, you know,

and I can start doing my
interface configurations from here

but everything always affects this.

Now look back at this chart.

Notice that once I'm in the
interface configuration mode,

I can always move back to global.

Well, how do I do that?

I got exit, so I can be in the interface
configuration mode, type in exit and bam,

I'm back out to the global configuration mode.

Now here is the key.

Remember, this is like the
different rooms of Myst.

The little widget, the timer that you spun
under the interface isn't going to work

from global for-- so for example, I type
in speed and hit the question mark--

not that key, I hit speed and hit
question mark and it's going--

I don't know what you're talking about.

Sorry, total invalid command.

Well, wait, wait a sec, what about duplex?

Duplex question mark-- nope,
sorry totally wrong command.

Ooh, do you see why?

I said knowing the modes is more valuable
because you can kind of reason your way

through it if you know what mode
to be in but if you're in global,

you won't even get the commands that
you need for that individual interface.

So, the commands that are in the interface don't
work in global and the commands for instance

when I typed in-- remember back
here, yeah, let me back up.

I typed in show IP interface
brief, I was in privileged mode.

So the commands that I type from privileged
mode, if I type in show IP interface brief,

it's like oh I'm sorry, you're off now.

Now notice even this, Cisco is trying to guide
me, it's going, "Hey, you went off right here."

It says invalid input detected
here and you're going, well, why,

that's how you spell show,
I mean it seems right.

Well, what it's saying is in
global configuration mode,

there's no commands that
start with anything SHO.

If I hit S question mark, you notice there's
a whole bunch of commands but there's only--

I can see-- let's see, I'm looking
for SH, there right there, shutdown.

So I have this shutdown which is it's saying,
okay, that was valid, but as soon as you went

into the O in global configuration mode, I
don't have any commands that start with SHO.

Now, if I go into the interface,
interface 0/1 and type in S question mark,

notice totally different set of commands
than what I had in global configuration mode.

Are you seeing it?

Are you seeing-- are you seeing the mode?

Now that is just two of the modes, that's global
and that's interface config but literally,

you know, we've got line config, router config
and this is just-- these are just examples,

this goes on to the hundreds of modes.

Each one dedicated to configuring
some aspect of your Cisco device.

Now, last thing I want to show you here
is-- notice I was sitting in these modes.

I can type in exit to move back
one level at a time, you know,

I got to-- it's getting just ugly.

I can type in exit and move back one
level at a time, so let me go back here.

I'm in interface config, I can exit to
global, exit back to privileged and then exit

out completely and now I'm
back-- back in user mode.

I'm going to type in enable, go back
into global, go under FastEthernet0/1.

I can also do what I would call a bailout.

You can do it one of two ways.

I can type in end and notice I'm dropped--

I'd skipped right past global and go all the way
back to configuration mode or privileged mode,

all the way back to the base, or I
can be in interface FastEthernet0/1

and hit control Z, and that
will also bail me out.

Now I actually like control Z better because no
matter where I'm at, I could be in the middle

of typing a command, I could be in
interface FastEthernet0/1 and type in--

well, the description of this
interface is connection to--

and I'm like I don't even want
to be here, control Z, bam.

It's like you're done at any point,
whereas if I would type in end,

it would think that's my description.

So control Z is the ultimate, at any
point, you bail out kind of command.

So there it is, that's the
welcome to the world of Cisco.

Like I said, if this were Windows, this would
have been like, okay, that's the start button,

that's the control panel, you know.

We aren't really saying what the control
panel does or what the start button is for

but you kind of get the idea of just
how to move around and navigate.

So here's what I want you to do with this.

I would like you-- before you dive
into the next nugget, if you can, well,

if you have some lab equipment, just
any Cisco device will do, get in there,

start navigating into user mode, into
privileged mode, into global config.

Start seeing what other modes there are.

Like for instance, you saw on that graphic
there was line mode or router mode.

You might look at that and
say, well, what are those?

You know, start gaining a little
curiosity of like what are some

of the things that I can do from these modes?

Don't worry if it's lab equipment,
now don't do it on production,

but if it's lab equipment,
you can't hurt anything.

You can just simply reboot the
device and it erases everything

that you did back to the beginning.

So get that familiar and play around with
that and then dive into the next nugget

where we're going to start getting into
the configuration of the switch itself.

For now I hope this has been informative for
you and I'd like to thank you for viewing.