WEBVTT

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 This video which belongs to section 2
.0 of the Cisco Certified Technician

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 Series in routing and switching is called
 Basic Cisco iOS Software Commands.

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 In this video I'm going to be your instructor
 and my name is Keith Bogart

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 and there's my contact information
 should you need to reach out to me

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 with any questions or comments
 that you might have.

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 So in the section 2.0 of the Cisco Certified
 Technician Blueprint it simply

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 says that you should be able to use
 and interpret the basic Cisco iOS

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 software commands.

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 So I'm going to include here what those
 commands are, gives her like a

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 high-level overview of what kind of
 output you would get from them.

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 So let's start out with some initial
 configuration commands.

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 These are the commands that I sometimes
 affectionately call convenience

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 commands and that they're not really
 commands that you have to do but

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 when configuring your router a switcher,
 switch if you put these commands

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 in it will make your life
 easier in the future.

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 So let's start with the first one which
 is the Logging Synchronous Command.

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 Now this command is done under your
 console port and I'll show you how

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 to get there in just a moment but the
 main idea behind this is that without

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 the logging synchronous command if
 you're in the middle of typing some

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 command or something and all of a sudden
 the router or switch decides

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 to print out a syslog message like an
 interface is just come up or come

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 down or any reason there's thousands
 of reasons why a syslog message might

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 be printed out. It will interrupt what
 you're typing which can be kind

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 of problematic if you don't exactly
 remember where you were to leave off

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 so I'll give you an
 example of that.

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 So first of all in order to check to see
 if the logging synchronous command

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 has already been pre-configured on a
 device you can just issue the command

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 show run and go all the way
 down to the console line.

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 There we go and if it was configured
 it would be right underneath there

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 in this case I don't see it.

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 So let me show you an example of
 why we might want to use that.

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 So I'm doing some configuration blah
 blah blah and let's say I'm done

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 with my configuration and I say okay
 I'm going to go ahead and exit back

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 out to privilege exec I want to issue
 the show running-config command

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 and verify my configuration however
 my typing is kind of slow so I type

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 exit and then show oh let's see look
 at that right there I wasn't done

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 with typing show running-config and
 yet this syslog message interrupted

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 me so it's now like okay well did I
 include the space did I not causing

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 some issues another issue that we can
 see right here and this is going

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 to be fixed by the next command is
 look at this I typed in an invalid

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 command I typed in show run altogether
 without spaces and the default

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 behavior of Cisco iOS is when you type
 in a command that doesn't recognize

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 like that it thinks it's a name it
 thinks it's a name of a device and

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 it tries to resolve that via DNS but
 let's take one thing at a time so

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 now if I go back in I'm going to go
 to line con zero that takes me to

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 my console port and that's where I'm
 going to type logging synchronous

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 and now if I exit out exit show see
 knows that I had just type sh and

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 it showed me my syslog I was interrupted
 but then it repeated what I typed

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 and where I left off so I can keep typing
 what it was that I was looking

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 for so that's where logging synchronous
 can really help you now that previous

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 command that we that previous error
 we saw show run where I forgot to

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 include the space and right now it's
 trying to interpret that and try

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 to resolve it via DNS what the moment
 if I hit enter enter any key on

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 my keyboard I'm getting nothing I have
 I am locked out until it gives

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 up so that brings us to our next command
 which is to prevent DNS resolution

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 attempts for mistyped commands and as
 a no IP domain dash lookup command

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 that's also a very useful command no
 IP domain dash lookup and now when

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 I mistyped something I'm immediately
 given my prompt back it does not

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 attempt to resolve that via DNS assuming
 I'm trying to tell net to some

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 name show run another convenience command
 but one that people do all the

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 time is to give a descriptive name to
 your router or your switch and that

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 is the host name command that is also
 done from global configuration mode

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 host name Keith dash switch now remember
 all these changes I'm making

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 here are purely affecting the running
 config they're not being saved to

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 the startup config in a previous video I
 showed you how to save your configuration

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 but I will rehash that again in this
 video as well so what else do we

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 want to look at how about some initial
 configuration commands for example

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 configuring a banner this also is purely
 optional don't have to do it

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 but the idea behind a banner is if
 you have a desire that when someone

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 logs into your router switch you want
 to automatically present them with

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 some kind of a message maybe a message
 that says this device owned by

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 it get out now or maybe a message that
 says the entire lab will be shut

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 down on Friday at 5 p.m.

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 for air conditioning repair whatever
 it might be that is what we call

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 a banner there are several different
 kinds of banners they they vary in

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 when they take effect for example there's
 some banners are displayed when

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 someone tell nets into a device there's
 some banners that display the

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 moment someone connects to the console
 of the device the one I'm going

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 to talk about is the method of the day
 or message of the day banner motd

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 message of the day and very simply
 here's how it works once again from

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 global configuration mode you type banner
 motd now the next thing you're

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 going to type is what's called a delimiting
 character this is any character

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 on your keyboard you know what's it used
 for well you type whatever character

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 you want and then you type your message
 and then the next time you type

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 that character again that's how ios knows
 that you're done with your message

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 so the key thing is your delimiting character
 should be picked as something

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 that is not going to be part of your
 message for example i'm going to

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 use the delimiting character of the
 letter p and i'll show you how this

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 is a problem now i say welcome to my
 router please leave now or die p

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 okay so you might think okay well sisco
 ios knows p is the delimiting

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 delimiting character and here it is
 i ended my line with the letter p

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 but notice the letter p was also part
 of my message and so what what that

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 actually means is the moment ios saw
 this letter p in the word please

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 it stopped in other words my banner
 right now is only going to reference

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 welcome to my router comma and that's
 it so i'm going to hit the enter

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 key and there it is everything from
 the p and please on after that was

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 discounted so what i really should
 have done was banner motd let's see

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 here welcome to my router please leave
 now well how about the carrot symbol

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 that's not part of my message welcome
 to my router please leave now carrot

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 symbol again and now you can see that
 the entire message is displayed

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 so that's what a banner is or a message
 of the banner and to undo that

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 you can just simply say no banner motd
 you don't have to copy the whole

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 banner back in again now this is something
 you're probably going to be

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 doing a lot adding ip addresses to
 an interface now keep in mind that

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 any interface whether it be an interface
 on the knit card of your laptop

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 on the Wi-Fi card built into your smartphone
 or on a router's interface

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 any interface that has an ip address
 also needs to have a subnet mask

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 an ip address without a subnet mask
 completely useless there's no way

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 for the device to know in that 32-bit
 address which of the bits of the

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 networking bits and which of the bits
 are the host bits now is the time

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 i am recording this video right now
 in order to add an ip address in the

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 subnet mask both components have to
 be added in dotted decimal notation

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 so you can see here step number one
 which isn't really shown as you go

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 into global configuration mode step
 number two is you tell the router

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 or switch which interface you want to
 get into and then you add your ip

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 address and subnet mask so let me get
 into a router here okay so i will

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 so that's global configuration mode
 right there now i'll go into one of

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 my interfaces with the interface fast
 ethernet zero slash zero so i'll

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 go into my very first fast ethernet
 interface and that's right type ip

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 address and give it some address followed
 by some subnet mask so the key

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 takeaway there is you have to think
 to yourself where is this ip address

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 going to be applied on what physical
 or what logical interface and then

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 from global configuration mode you
 need to get into that interface and

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 then apply the ip address all right
 let's take a look at some commands

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 that that monitor certain things for
 example what if i want to see what

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 ip addresses i have on my interfaces
 and whether those interfaces are

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 up or down or administratively shut
 down well for that i use the show

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 ip interface brief command and that'll
 work on both routers and switches

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 let me go ahead and do it on a router
 here show ip interface brief it's

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 a great command you can see it shows
 you the interface name and number

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 the ip address it has or maybe doesn't
 have one at all tells you if that

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 ip address was manually configured which
 it probably was some other options

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 are DHCP or serial line ARP and also
 shows you the status of the interface

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 in this case status is up up or is this
 one is administratively down so

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 show ip interface brief how about displaying
 the physical layer status

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 of interfaces for example on this interface
 right here i can see that's

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 up i can see it has an ip address but
 what is the speed of that interface

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 what's the bandwidth what is the duplex
 is it half duplex full duplex

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 does it have any errors has it any fcs
 errors or drops so i can do that

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 by typing show interface and then the
 interface i'm concerned with show

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 interface fast ethernet zero zero in
 this case and here we can see once

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 again it reinforces that the interface
 is up gives me information like

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 the MAC address if i if i need to know
 the MAC address of the interface

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 reinforces if the interface has an
 ip address or not and that gives me

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 a lot of lower level stuff for example
 the MTU the bandwidth on the interface

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 what type of encapsulations being used
 there in this case is doing full

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 duplex one hundred megabits per second
 and then down here the last section

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 shows me all of my error counters if
 there's any errors whatsoever as

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 well as statistics about packets input
 as well as packets output that

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 is the show interface command now on
 routers router interfaces are always

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 layer three interfaces we call them routed
 interfaces we don't even really

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 column that we just call them interfaces
 now on a switch especially a

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 multi-layer switch and most of the
 switches that Cisco sells are multi

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-layer switches a switch's interface
 could be a switch port which means

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 there's no IP information on it it doesn't
 even understand IP it's just

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 part of a VLAN it's switching layer
 two frames back and forth that's a

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 switch port or it could be a routed interface
 like an interface on a router

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 or it could be a trunk it could be
 a variety of things so how do i see

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 what the switch port operating mode
 is on a switch interface and if it's

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 trunking some trunking information well
 i can do that same command i just

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 did before show interface but this time
 use the special keyword of switch

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 port on the end of that interface so
 for example so here if i go on to

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 show interface fast ethernet zero slash
 ten switch port so unlike just

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 the show interface command which shows
 me a lot of low level physical

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 layer information like errors encounters
 this one gives me more layer

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 two feature information so it tells me
 switch port enabled in other words

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 this is not a routed port i can't put
 an IP address on here this is a

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 layer two switch port it tells me that
 right now operationally it's operating

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 as concerned the native VLAN is VLAN4
 and there's a whole bunch of other

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 good stuff in here from this command
 as well now what if i did the same

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 command on a port that's a routed port
 a port that's like a port on a

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 router where i put an IP address well
 i'll get absolutely nothing back

0:15:50.680000 --> 0:15:55.700000
 because this command here with the keyword
 switch port assumes that the

0:15:55.700000 --> 0:15:59.540000
 interface you're looking at is a switch
 port for example if i do show

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 interface fast ethernet zero slash
 one switch port it says switch port

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 disabled this is not a switch port because
 if i actually take a look at

0:16:11.740000 --> 0:16:17.020000
 it you can see i actually typed in the
 no switch port command which converted

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 it into a layer three routed interface
 which allowed me to put an IP address

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 and subnet mask on it also if you have
 a question if you might say hey

0:16:27.440000 --> 0:16:31.580000
 i wonder if my switch has any VLAN trunks
 i'm not sure which interfaces

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 if any of them are VLAN trunks you can
 get a high level summary of this

0:16:34.880000 --> 0:16:44.700000
 with a show interface trunk command
 show interfaces trunk and we can see

0:16:44.700000 --> 0:16:50.080000
 here that i've got four trunks these
 four ports right here are currently

0:16:50.080000 --> 0:16:55.160000
 trunking you can see the end means
 they dynamically negotiated to 802

0:16:55.160000 --> 0:16:59.880000
.1q trunking encapsulation it also gives
 you information about the native

0:16:59.880000 --> 0:17:05.080000
 VLAN on each trunk which VLANs are allowed
 in the event that you may have

0:17:05.080000 --> 0:17:10.480000
 manually stripped off certain VLANs
 from the trunk and which VLANs are

0:17:10.480000 --> 0:17:17.560000
 actually configured and active in the
 switch right now how about monitoring

0:17:17.560000 --> 0:17:24.040000
 of routing protocols how do i see my routing
 table with IP it's just simply

0:17:24.040000 --> 0:17:34.620000
 show IP route and if you have learned
 of any routes they're going to be

0:17:34.620000 --> 0:17:39.020000
 in here so the first part of show IP
 route gives you a key which means

0:17:39.020000 --> 0:17:42.800000
 because every single route is prefenced
 by some sort of a letter and this

0:17:42.800000 --> 0:17:46.720000
 key up here will tell you what that
 letter means so for example we can

0:17:46.720000 --> 0:17:51.840000
 see that r means rip so here's a route
 that was learned via rip we can

0:17:51.840000 --> 0:17:58.460000
 see that o is ospf and ia is ospf inter
-area so we've got an ospf inter

0:17:58.460000 --> 0:18:05.840000
-area route d what's that what we can
 see right here d is eijrp now if

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 you do happen to be running ipv6 in
 your network the same command will

0:18:09.720000 --> 0:18:16.100000
 work with just a slight modification
 show ipv6 route so either show ip

0:18:16.100000 --> 0:18:22.500000
 route for your ip version for routing
 protocol or show ipv6 route i'm

0:18:22.500000 --> 0:18:25.420000
 not running ipv6 in here so i'm not
 going to demonstrate that for you

0:18:25.420000 --> 0:18:31.000000
 okay maybe you wonder what routing
 protocols are currently running on

0:18:31.000000 --> 0:18:36.160000
 my router right now for example maybe
 you say hey i thought i had rip

0:18:36.160000 --> 0:18:41.700000
 and ospf running on my router but i'm
 only seeing ospf routes did somebody

0:18:41.700000 --> 0:18:46.260000
 forget to configure rip well you can
 use the command show ip protocols

0:18:46.260000 --> 0:18:53.600000
 to display that once again even though
 i'm doing this on a switch don't

0:18:53.600000 --> 0:18:57.600000
 be misled this is a layer three switch
 so it's capable of all the same

0:18:57.600000 --> 0:19:11.240000
 routing that routers are capable of doing
 show ip protocols so i've actually

0:19:11.240000 --> 0:19:16.420000
 configured a lot of stuff on here so you
 can see here that the first routing

0:19:16.420000 --> 0:19:21.700000
 protocol list is eijrp gives a lot of
 good information about that protocol

0:19:21.700000 --> 0:19:29.300000
 like the eijrp autonomous system number
 the k-values the router id the

0:19:29.300000 --> 0:19:33.920000
 administrative distances for eijrp
 further on beneath that you can see

0:19:33.920000 --> 0:19:40.360000
 it's running ospf and shows you information
 about ospf as well and it's

0:19:40.360000 --> 0:19:44.300000
 also running rip so this is a good command
 to see what routing protocols

0:19:44.300000 --> 0:19:51.080000
 are currently active on my device now
 for those routing protocols that

0:19:51.080000 --> 0:19:59.020000
 do create neighbor relationships like
 ospf eijrp isis and bgp you can

0:19:59.020000 --> 0:20:04.460000
 use the show ip protocol and the neighbor
 command to see do you have any

0:20:04.460000 --> 0:20:08.180000
 neighbor relationships for example
 on my particular switch i'm running

0:20:08.180000 --> 0:20:13.880000
 eijrp and ospf in order for that to actually
 work my switch needs to form

0:20:13.880000 --> 0:20:18.720000
 an eijrp neighbor relationship with another
 device running eijrp and with

0:20:18.720000 --> 0:20:23.100000
 another device running ospf has it
 done so well i can use this command

0:20:23.100000 --> 0:20:30.120000
 right here to do that show ip eijrp
 neighbor just the fact that i see

0:20:30.120000 --> 0:20:34.820000
 anything shows me it is it does have an
 eijrp neighbor i can see the address

0:20:34.820000 --> 0:20:40.440000
 of my eijrp neighbor the interface where
 i learned it and how long i've

0:20:40.440000 --> 0:20:45.860000
 had an eijrp neighbor you can do the
 same thing for ospf show ip ospf

0:20:45.860000 --> 0:20:51.440000
 neighbor shows me having ospf neighbor
 and as you learn more about these

0:20:51.440000 --> 0:20:55.940000
 routing protocols you'll learn what
 these various pieces of information

0:20:55.940000 --> 0:21:02.480000
 under each column stand for do i have
 any other sysco devices connected

0:21:02.480000 --> 0:21:08.140000
 most not all but most sysco devices
 certainly routers and switches by

0:21:08.140000 --> 0:21:13.700000
 default run a sysco proprietary protocol
 called the sysco discovery protocol

0:21:13.700000 --> 0:21:19.120000
 cdp and basically what cdp does is it
 just periodically about once every

0:21:19.120000 --> 0:21:24.700000
 minute or so sends out a cdp message
 saying hey here i am here's my host

0:21:24.700000 --> 0:21:29.000000
 name here's what kind of device i am
 here's my host software i'm running

0:21:29.000000 --> 0:21:33.300000
 and so if i'm sitting on a sysco device
 i can see if it has learned of

0:21:33.300000 --> 0:21:38.200000
 any incoming cdp messages from directly
 connected neighbors now cdp messages

0:21:38.200000 --> 0:21:42.120000
 do not hop from one device to the other
 so when i issue this command show

0:21:42.120000 --> 0:21:46.480000
 cdp neighbor i will only see devices
 that are directly connected to me

0:21:46.480000 --> 0:21:53.900000
 if they're also running cdp i won't
 see any devices beyond them so for

0:21:53.900000 --> 0:22:01.120000
 example here you can do show cdp neighbor
 and you can see i've learned

0:22:01.120000 --> 0:22:05.560000
 quite a few cdp neighbors it shows
 me that the name which defaults to

0:22:05.560000 --> 0:22:09.860000
 the host name of the device the local
 interface is the interface on my

0:22:09.860000 --> 0:22:14.740000
 device to the one i'm on right now that
 learned of this neighbor and the

0:22:14.740000 --> 0:22:20.500000
 port id over here is the remote interface
 for example on my local interface

0:22:20.500000 --> 0:22:24.120000
 i'm connected to some sort of device
 looks like it's a router because

0:22:24.120000 --> 0:22:29.880000
 it's got an r here called client-router2
 i am connected to him on fast

0:22:29.880000 --> 0:22:35.760000
 ethanet02 but if i found fast ethanet02
 and i trace that cable the other

0:22:35.760000 --> 0:22:40.120000
 end of that cable will be connected to
 that router's fast ethanet00 interface

0:22:40.120000 --> 0:22:46.420000
 you can also use the command show cdp
 neighbor detail and get even more

0:22:46.420000 --> 0:22:53.520000
 detailed information about those cdp
 neighbors show version very useful

0:22:53.520000 --> 0:22:57.260000
 command to see what ios version you're
 running as well as all sorts of

0:22:57.260000 --> 0:23:13.760000
 other information show version so here
 in show version it shows that this

0:23:13.760000 --> 0:23:19.280000
 is a catalyst 3560 shows you the feature
 set or technology train that's

0:23:19.280000 --> 0:23:27.120000
 in use also shows you it's running 12255
 se9 software this is some critical

0:23:27.120000 --> 0:23:29.920000
 information that the syscode tack will
 need to know if you're dealing

0:23:29.920000 --> 0:23:34.440000
 with them when troubleshooting a case
 also shows you how long that device

0:23:34.440000 --> 0:23:39.460000
 has been turned on three hours and 33
 minutes the last time it was turned

0:23:39.460000 --> 0:23:44.520000
 on was due to a power on so it wasn't
 a crash or anything gives you a

0:23:44.520000 --> 0:23:47.300000
 lot of other good information as well
 it types of interfaces and modules

0:23:47.300000 --> 0:23:57.940000
 it has part numbers and serial numbers
 and it also if i do this for example

0:23:57.940000 --> 0:24:05.300000
 on a router at the very bottom of the
 show version command you also see

0:24:05.300000 --> 0:24:09.960000
 information about your configuration
 register that's a topic i'm going

0:24:09.960000 --> 0:24:19.280000
 to talk about in the next video the
 configuration register so syscode

0:24:19.280000 --> 0:24:22.640000
 routers and switches have lots of different
 types of memory we've talked

0:24:22.640000 --> 0:24:28.040000
 in earlier videos i've talked about nvram,
 dram, flash memory, raw memory

0:24:28.040000 --> 0:24:33.240000
 so directory all will show you what
 type of memories in the device and

0:24:33.240000 --> 0:24:43.000000
 what files are stored there so for
 example if i do this in my switch d

0:24:43.000000 --> 0:24:55.500000
-i-r and then all so the switch starts
 with flash memory so here's my flash

0:24:55.500000 --> 0:24:59.940000
 memory and as can be expected in the flash
 memory is my syscode iOS software

0:24:59.940000 --> 0:25:06.420000
 image system memory is the same as
 dram that's the same thing as dram

0:25:06.420000 --> 0:25:11.280000
 and in dram we know we can expect to
 find our running config that's in

0:25:11.280000 --> 0:25:15.900000
 there now switch this switch also has
 something called temp-sis i've no

0:25:15.900000 --> 0:25:18.720000
 idea what that is i've never needed
 to know it's got a whole bunch of

0:25:18.720000 --> 0:25:23.440000
 other junk in there and then nvram
 we can see my startup config is in

0:25:23.440000 --> 0:25:29.120000
 there so that was all the result of
 using the d-i-r space all directory

0:25:29.120000 --> 0:25:36.100000
 all command and these two commands
 you're probably familiar with show

0:25:36.100000 --> 0:25:43.700000
 startup config and show running dash
 config so show startup dash config

0:25:43.700000 --> 0:25:49.500000
 will show you what configuration file
 will be used the next time this

0:25:49.500000 --> 0:25:57.020000
 device power cycles in this case the
 star configurations not present and

0:25:57.020000 --> 0:26:02.140000
 we can see that right here because the
 start configuration says zero however

0:26:02.140000 --> 0:26:06.800000
 if i do show running config i do have
 a running config in this device

0:26:06.800000 --> 0:26:12.700000
 which tells me that when this thing was
 first powered on it had no startup

0:26:12.700000 --> 0:26:16.900000
 configuration at all some changes have
 been made to it clearly you know

0:26:16.900000 --> 0:26:21.900000
 ei jr p ospf rip have been added to
 it but those changes have not been

0:26:21.900000 --> 0:26:28.960000
 saved if they had been saved i would
 have a startup config which leads

0:26:28.960000 --> 0:26:32.800000
 me to my next slide how do i save those
 changes from the running config

0:26:32.800000 --> 0:26:36.160000
 to the startup config because we know
 that all this stuff will be lost

0:26:36.160000 --> 0:26:45.440000
 when the power goes out i need to save
 that well there are two ways you

0:26:45.440000 --> 0:26:52.160000
 can do it uh the long way is the copy
 running dash config a space startup

0:26:52.160000 --> 0:26:58.380000
 dash config or you can simply type right
 memory or even just wr for right

0:26:58.380000 --> 0:27:03.260000
 they both do the exact same thing so
 the copy command the way it works

0:27:03.260000 --> 0:27:10.380000
 is copy after the copy is your from
 location what am i copying from well

0:27:10.380000 --> 0:27:20.920000
 i'm copying from my running config for
 example to a tftp server i could

0:27:20.920000 --> 0:27:25.220000
 do it like this copy running config
 tftp and then it would prop me it's

0:27:25.220000 --> 0:27:28.820000
 say okay what's the IP address of the
 tftp server but i'm not going to

0:27:28.820000 --> 0:27:33.400000
 do that in this case i'm going to do
 copy running config and i want to

0:27:33.400000 --> 0:27:38.180000
 save it to the startup config that
 says okay do you want your running

0:27:38.180000 --> 0:27:42.860000
 config when you're saving it to be
 called startup config absolutely i

0:27:42.860000 --> 0:27:47.320000
 do so i just hit enter now that exact
 same thing can be done with just

0:27:47.320000 --> 0:27:52.480000
 two key strokes wr it's the exact same
 thing is copy running config to

0:27:52.480000 --> 0:28:00.820000
 start config and say i'm setting a router
 back to factory defaults here

0:28:00.820000 --> 0:28:03.320000
 are the commands to do that i'm not
 going to go into the details of that

0:28:03.320000 --> 0:28:06.480000
 because i actually demonstrated that
 in the previous video when i was

0:28:06.480000 --> 0:28:09.480000
 talking about saving configuration
 files so i'm not going to spend any

0:28:09.480000 --> 0:28:14.720000
 detailed time here going about that
 a couple more things let's talk a

0:28:14.720000 --> 0:28:21.280000
 little bit about some real basic security
 commands so we want to secure

0:28:21.280000 --> 0:28:25.860000
 the enable password we know that when
 someone first gains console access

0:28:25.860000 --> 0:28:30.240000
 to my router and my switch they're
 going to be in user exec mode not a

0:28:30.240000 --> 0:28:33.620000
 lot of damage they can do from user exec
 mode because they can't configure

0:28:33.620000 --> 0:28:39.180000
 anything but if they issue the enable
 command and get right into privilege

0:28:39.180000 --> 0:28:43.220000
 exec well from there they've got full
 access they can do anything they

0:28:43.220000 --> 0:28:46.980000
 want to my router my switch so i probably
 want to password protect that

0:28:46.980000 --> 0:28:51.780000
 level either with an enable password
 or an enable secret password what's

0:28:51.780000 --> 0:28:56.440000
 the difference well functionally they
 both do exactly the same thing whether

0:28:56.440000 --> 0:29:00.820000
 i do enable password or enable secret
 it simply means that when someone

0:29:00.820000 --> 0:29:04.980000
 types the enable command they're going
 to be given a password prompt and

0:29:04.980000 --> 0:29:09.960000
 they're going to type in between the two
 of these things is really historical

0:29:09.960000 --> 0:29:15.560000
 in nature the enable password came
 out first and we can see if i type

0:29:15.560000 --> 0:29:22.940000
 enable password and then put some password
 on there like sisco well now

0:29:22.940000 --> 0:29:26.800000
 if i get in here and i try to enable
 i'm prompted with a password prompt

0:29:26.800000 --> 0:29:31.760000
 and i have to type sisco it has to be
 exact the case it is case sensitive

0:29:31.760000 --> 0:29:37.020000
 now what some people perceived as a
 problem with the enable password was

0:29:37.020000 --> 0:29:42.540000
 that if i need to send my configuration
 to someone to look it over like

0:29:42.540000 --> 0:29:46.260000
 maybe sisco tack or another co-worker
 and i just issued the show running

0:29:46.260000 --> 0:29:51.740000
 config command you'll see that your enable
 password is right here in plaintext

0:29:51.740000 --> 0:29:56.240000
 so now you may have inadvertently given
 away your enable password that's

0:29:56.240000 --> 0:29:59.940000
 the main problem with it so then later
 on i'm not sure how much time elapsed

0:29:59.940000 --> 0:30:04.140000
 but later on some sisco engineers said
 well we should have it to wear

0:30:04.140000 --> 0:30:08.300000
 when they type in the password it's
 automatically encrypted for them so

0:30:08.300000 --> 0:30:12.820000
 it doesn't show up in plaintext format
 and that's what the enable secret

0:30:12.820000 --> 0:30:20.020000
 is for enable secret i'll just use the
 word i and e for that and now you

0:30:20.020000 --> 0:30:23.840000
 can see when i look at my show running
 config output the enable secret

0:30:23.840000 --> 0:30:30.180000
 has been hashed with an md5 hashing algorithm
 now this is not uncrackable

0:30:30.180000 --> 0:30:35.780000
 it's just extremely difficult to uncrack
 that so i should say to crack

0:30:35.780000 --> 0:30:40.360000
 that so it's just more secure now in
 this particular case if you happen

0:30:40.360000 --> 0:30:45.880000
 to have both an enable secret and an
 enable password the enable secret

0:30:45.880000 --> 0:30:50.640000
 always takes priority it's basically
 like the enable password isn't doing

0:30:50.640000 --> 0:30:55.560000
 anything so if i try to get out right
 now and now i type enable if i try

0:30:55.560000 --> 0:31:01.500000
 typing sisco c-i-s-c-o it won't take
 it it's expecting me to type in i

0:31:01.500000 --> 0:31:06.160000
 and e which is my enable secret and
 the way you undo those or get rid

0:31:06.160000 --> 0:31:14.000000
 of them is simply by typing no enable
 secret and no enable password and

0:31:14.000000 --> 0:31:21.680000
 that gets rid of them you can also
 put a password on your console port

0:31:21.680000 --> 0:31:25.980000
 so if anybody connects to the console
 now presumably your routers and

0:31:25.980000 --> 0:31:29.620000
 switches are locked away in a wiring
 closet or a lab somewhere where only

0:31:29.620000 --> 0:31:33.720000
 people who have special keycard access
 can get to them but if you have

0:31:33.720000 --> 0:31:36.860000
 a lab where a lot of people use that
 lab from different departments or

0:31:36.860000 --> 0:31:39.920000
 different parts of the company you might
 have routers or switches within

0:31:39.920000 --> 0:31:43.820000
 that lab that you don't want anybody
 getting to even if they're physically

0:31:43.820000 --> 0:31:48.020000
 in front of it so by putting a password
 on the console you can lock them

0:31:48.020000 --> 0:31:51.220000
 out you very careful with that though
 if you put a password on the console

0:31:51.220000 --> 0:31:57.760000
 because you could also inadvertently
 lock yourself out as well and the

0:31:57.760000 --> 0:32:01.420000
 last things i want to talk about as
 far as securing sisco devices are

0:32:01.420000 --> 0:32:07.140000
 some more passwords and this is putting
 a password on your telnet connection

0:32:07.140000 --> 0:32:11.200000
 so someone's trying to telnet in to your
 router we want to make sure that

0:32:11.200000 --> 0:32:15.260000
 they're presented with a password prompt
 so you have two choices for this

0:32:15.260000 --> 0:32:23.560000
 in the first option we're going into
 our vty lines line vty 04 now this

0:32:23.560000 --> 0:32:27.940000
 means in this particular platform there
 are there's the potential of having

0:32:27.940000 --> 0:32:32.920000
 up to five simultaneous telnet sessions
 happening i'm not sure when that

0:32:32.920000 --> 0:32:36.760000
 would ever happen that five people would
 be telnetted into this one box

0:32:36.760000 --> 0:32:40.800000
 all at the same time i suppose it could
 happen but that's what this means

0:32:40.800000 --> 0:32:45.780000
 the first person's going to get vty
 0 second person's going to get vty

0:32:45.780000 --> 0:32:51.240000
 1 all the way up to vty 4 and then
 under my vty line i'm going to put

0:32:51.240000 --> 0:32:55.700000
 password and then whatever i want my
 password to be now if i do it like

0:32:55.700000 --> 0:33:00.220000
 that that means anybody and everybody
 that telnet sent to this device

0:33:00.220000 --> 0:33:05.220000
 will be prompted for a password and they'll
 all have the exact same password

0:33:05.220000 --> 0:33:09.300000
 now that could be problematic imagine
 from moment that i have a fairly

0:33:09.300000 --> 0:33:14.740000
 large staff of let's say 25 network
 admins in my company on all of my

0:33:14.740000 --> 0:33:21.440000
 hundreds of routers and switches i put
 a password of sisco 1 2 3 and now

0:33:21.440000 --> 0:33:24.860000
 i have to fire one of my network admins
 because i've found them doing

0:33:24.860000 --> 0:33:29.400000
 some unethical stuff in the company
 well as they walk away they still

0:33:29.400000 --> 0:33:33.320000
 know that sisco 1 2 3 is the password
 which means now they have to get

0:33:33.320000 --> 0:33:38.040000
 into every single device change the
 password on every single device and

0:33:38.040000 --> 0:33:42.240000
 let all the remaining network admins
 that still work for me know what

0:33:42.240000 --> 0:33:46.680000
 the new password is that's kind of
 a hassle so what might be better is

0:33:46.680000 --> 0:33:49.980000
 the second option and the second option
 you can see here that at the global

0:33:49.980000 --> 0:33:55.040000
 configuration level we're starting by
 creating unique username and password

0:33:55.040000 --> 0:34:00.420000
 statements for each person so in my particular
 case i might have 25 unique

0:34:00.420000 --> 0:34:05.860000
 username and password statements and
 then when somebody logs in via telnet

0:34:05.860000 --> 0:34:10.520000
 they're presented with a username and
 a password prompt and if i happen

0:34:10.520000 --> 0:34:13.820000
 to lay somebody off or fire them i'll
 just get rid of that one username

0:34:13.820000 --> 0:34:17.280000
 and password prompt and it won't affect
 the other people in my company

0:34:17.280000 --> 0:34:20.420000
 so let me just show you some demonstrations
 of this and then we'll finish

0:34:20.420000 --> 0:34:25.540000
 that up for this video so first of all
 i'm going to go ahead and go into

0:34:25.540000 --> 0:34:37.100000
 line vty 04 and i'm going to say password
 sisco so now when someone tries

0:34:37.100000 --> 0:34:43.920000
 to telnet in they get the password
 prompt and as long as they know the

0:34:43.920000 --> 0:34:53.400000
 correct password they're in there they
 go now instead i'm going to type

0:34:53.400000 --> 0:35:02.620000
 username keith password sisco and go
 back to my vty lines i'm going to

0:35:02.620000 --> 0:35:10.640000
 say no password instead i'm going to
 say log in local that means hey when

0:35:10.640000 --> 0:35:15.060000
 somebody logs in there is authentication
 information but it's not here

0:35:15.060000 --> 0:35:20.240000
 under the vty look at the global configuration
 level to find that information

0:35:20.240000 --> 0:35:29.080000
 so now when i get out if i try to telnet
 into that same device now i get

0:35:29.080000 --> 0:35:32.860000
 a username prompt type in the username
 it is case sensitive type in the

0:35:32.860000 --> 0:35:38.880000
 password oh i think i messed up because
 i use the capital c in sisco it

0:35:38.880000 --> 0:35:44.180000
 should have been a lower case c let's
 try it again keith c-i-s-c-o and