Basic Switch Configuration

starting the switch it's so ironic the switch typically does not have a power switch yeah the switch typically does not have a power switch so what it is going to happen is you are going to go in and you are going to verify that your cabling is all set and then once your verify the cabling you're going to go ahead and you're going to provide the lower end Cisco switch that doesn't have an on or an off switch you're going to go ahead and provide that device with power once you provide that device with power you verified your connections then the switch is going to go ahead and initiate its startup routines and you can go ahead and observe the pretty lights that are blinking all over the device right yeah the LEDs that are there to give you status indications to give you health information about the particular device and its equipment let's hear from a guest expert that we have yet to hear from in this class I don't believe we've heard from Jeff Hardy Jeff is a longtime very successful Cisco network engineer for a fortune 500 company let's hear from Jeff about the LEDs that we have on switches and Cisco devices in general Jeff go ahead and take it away for us if most switches are tucked away in closets or data centers when will you have the opportunity to examine the LED indicators when something's wrong of course luckily there are programs that will show you the LEDs remotely for quick glance to see if there are any issues and that's mostly what they're for in my opinion the majority of the time I log into a switch remotely and either look at the interface status of the CLI or look at recent logs to begin pinpointing issues the LEDs can be useful if you're familiar with them and can't log in remotely to a switch so just before I consult in I'll look at the LEDs to see if there are any obvious problems like no green lights where there should be green lights however the LED indicators and modes do vary by switch model in many environments you will have a few models to contend with so it's up to you if it's worth memorizing different modes and indicators on each model you will want to know the specifics for the model indicated in the exam though but in the field probably the best use for the mode button is holding it down while rebooting the switch in order to perform password recovery well great stuff thanks so much Jeff awesome and I am just about ready to connect to a rack of equipment for demonstrations today and still just struggling with that it was all setup moments before class but then you know how that works there are issues with it just before the class actually kicks off so just give me one minute here in the background to get our equipment set up that we're going to use for our practice today alright it looks like we're there great so here I have just logged in to a Cisco switch and what I did was we made a console connection to this device right and we are observing what's happening here at the console for that particular device and it looks like all kinds of stuff is happening as this switch is already wrapped up and cabled with a bunch of other Cisco switches and routers and all this equipment has just been powered on so we're seeing all of this stuff initialize here on this particular device and I've got an interesting quandary here I noticed that this device is named switch one see that and we talked about this last time this is the name of the device and there is a greater than prompt and that greater than prompt is indicating that we're in user mode remember how we go into privileged mode is by typing enable that gets us into this privileged mode but I told you I had a problem here my problem is that this device must have a configuration wait a minute I want to show you what happens when the device has no configuration whatsoever yeah exactly JB says in the queue who changed the name that's right I want this to be like a factory default switch so let's do this let's pretend this switch was given to us by a friend and we want to erase the startup configuration we call the saved configuration remember in non-volatile Ram we call that saved configuration the startup - config so I want to erase the startup config the switch says are you absolutely sure you want to do something like that so I say yeah absolutely I want to erase that startup config and I hit enter to confirm that now if I reload we should be at factory defaults with one important exception there is something called a VLAN database and that is not part of that startup configuration and that VLAN database we'll get more into VLANs later but let me just show you this very interesting that VLAN database is part of flash it's stored in flash so I'm going to go erase or actually delete excuse me delete out of flash the VLAN dot database VLAN dot dot and it says dummy you must be in privilege mode to do that so I'm going to use the N command and I'm going to highlight that command copy it to the clipboard and paste it in alright so delete VLAN dot dat out of the flash now Isaac says what about erase NVRAM um yeah I wouldn't do that I'd be much more specific right I would go ahead and say look I want to erase the startup-config and let me tell you Isaac remember for your exam only certain commands will work and I know for an absolute fact uh erase startup-config will work ok so we'll emphasize that command in here okay so we have erased the startup configuration we have erased any VLAN database that might be on the device so I think we're ready to go ahead and reload we say reload it says are you sure you want to do this without saving any configuration and we say yes and the switch is reloading why it's reloading because we use the reload command now how how in the world wait a minute I need to do something else here boy everything got all messed up here just one moment one moment is I fix one more thing just doing some housekeeping on my windows setup here and we're not missing anything because we're just waiting for that switch to reboot aren't we yep we're just waiting for the switch to reboot and here we go and we can watch that process as you can see what is going on with all those characters that is a graphical representation of the operating system being expanded into RAM on the device pretty cool all right going through its power on self test or post of all of its hardware and it looks like we're about done with this reload of the switch and remember what we did we erased all configuration of the switch and it drops us off at press return to get started and then we get a bunch of more output of the interfaces initializing on this device but remember what it last said to me press return to get started so I'll hit return on the keyboard and look at this I think we talked about this last class didn't we there is no configuration on this device so it offers to guide us through an initial configuration of this device this is called the setup script and just about all of your Cisco devices will have this it's kind of like a wizard if you think about Microsoft technologies and it wants to guide you through in this case at least an initial configuration of this particular device notice it says would you like to do this and then we have to respond yes or no if we hit enter it just keeps asking us the question because we are not providing one of the two options for answer now I never use the setup script I'll be honest with you but just to show you what it's like let me in this case say yes we want to be handheld through this configuration it then says would you like to enter basic manage setup I'll go ahead and say yes it says alright what would you like to name your switch I'll give it the very distinct name of my switch okay what would you like the enable secret password to be I'll say Cisco it says what's the enable password I'll say San Fran it says what's the virtual terminal password I'll say Cisco do you want to configure SNMP I'll say no by hitting enter and accepting the default command it shows me all the interfaces it asked me what interface name are we going to use to connect to the management network I'll say that we're going to use VLAN one to connect to the management network it asks me if I want to configure IP on the interface I'll say no would we like to do clustering no and then it shows me what configuration is going to result from all of those inputs and then it gives us three options 0 we can go to the command prompt without saving we can rerun the script or we can save this configuration to NVRAM and exit we're going to do the hysterical thing here because this was just for demonstration I'm going to hit 0 and we just did all that for nothing and we are returned to the user mode switch prompt and we can go ahead and configure this switch from scratch now can't we yep we'll configure it from scratch notice switch greater than sign the switch greater than sign remember indicates we are in user mode when we type enable we go to privileged mode when we type disabled we exit privileged mode and go back into user mode okay so enable table and these are all things that I want you to practice and your hands on lab work you know type enable make sure you go into privilege mode type disable make sure you go back into user mode you need to be able to configure a switch in your exam environment and you need to be able to do it quickly and with confidence and you need to be able to verify your config so that you know that you got the points and the only way you're going to be able to do all that is with consistent constant practice before your exam for those of you that are taking an exam now you want to give your switch a name you want to give your switch a name so we say enable okay and we get into privilege mint mode but if you say hostname question mark it says I don't know what you're talking about why doesn't it know what we're talking about well because if you go H OS question mark you'll see there is no command in privileged mode that will allow you to name your switch instead we have to go into something called global configuration mode notice the prompt just changed again and now we can make changes to the switch that will have a global impact one of the globally impactful changes will be to give this switch a new host name yep and we do that with the host name command in global configuration mode no configure terminal to get in global configuration mode and then we can go ahead and name the switch appropriately anyone in the live audience got a name for me I'm just not feeling very creative today anybody got a name for my switch we'll take the first one in as long as it's clean this is a family show all right Steve says s GFS you got it so now we have a switch named s g f s now this is a layer to switch okay by the way what's funny is in all reality this is a layer 3 switch that we're on but I have not turned on its routing capabilities okay we are not going to use this particular device as a router ok we've decided not to and we're talking about layer 2 switches so that's a good decision let me prove that to you I'm going to type N and then I'm going to do this show IP route and it does not show me a routing table it shows me an ICMP redirect cache this means that this is not a route a switch right now that's set up to route good good so it is a layer 2 switch that's what I want now I'm going to teach you how we can assign an IP address to this particular device but wait a minute before I teach you how to assign an IP address to this device let's ask a very important question here why would you even want an IP address a layer three IP address on a layer 2 switch this isn't making any sense we have a layer 2 only thing why are we putting an IP address on it and everybody is already answering me in the audience great job you are such a sharp bunch it's so we can manage it remotely it's so we can secure shell or telnet into this device in order to manage this device from somewhere far away now how you put a management IP address on the device is you go in and you go into what's called interface vlan1 this is a default VLAN that is participating on all of your ports so this is a great place initially to put an IP address for management so we say interface VLAN virtual local area network one will talk more about VLANs later don't worry interface VLAN 1 IP address and then whatever IP address that we are going to assign to this device and notice you follow that up with a subnet mask don't worry we'll talk more about subnet masks and IP addresses later on ok but notice for right now just stay with me we are just giving this thing its IP address for management purposes now wait a minute if we come in from some far away place we are never going to be able to communicate back to that far away place unless we have a router to help us so one of the other configurations I want you to master today is the configuration of a default gateway a local router that can have this switch get its traffic off of the local segment and this default gateway configuration is done in global configuration mode so we're going to exit from interface configuration mode and I'm going to say IP default gateway and I'm going to give the default gateway address let's pretend we have a local router at 10.5 dot v dot 100 and now we can use that local router to route traffic out of our local segment well my goodness we've done a lot of great configurations to the s GFS device and I think we better save all of that configuration so let's go in and save this config with copy running - config - startup - config copying the configuration from RAM to non-volatile Ram on the device so we go in and we say copy running-config to startup config copy running-config to startup config and now we can reload this device and this configuration will still be available for us pretty awesome now let's do some confirmations here we saved the configuration to the startup config let's see it worked show startup-config hi worked the startup-config has our host name assignment the startup-config has our VLAN interface IP address the startup config has our default gateway assignment pretty awesome so show run or show startup config allows you to see those things what about verifying what type of device I'm on show version show version tells you what you're on a thirty five sixty type device here's the operating system it's running what version of the operating system that is it is specifically a thirty five sixty type device great stuff great information it tells us how long this device has been powered up and that's fourteen minutes there has been some fantastic examples of Cisco device show version output where we see switches that have been available for literally years and years and years without rebooting Steve asks when you're setting the IP address by the way do you have to type it out longhand like that yes you do Steve on this Cisco device you can't use a shortcut and remember when you're practicing something like that try it won't hurt right interface FA 0/0 there isn't one interface fastethernet 0/1 IP address let me go to interface vlan1 where we can assign an IP address IP address 10 dot v dot v dot 11 and steve wants to do slash 24 and it says nope sorry can't do it so don't be afraid absolutely experiment in your lab as you are working with these commands ok absolutely great idea for you to experiment it's just lab equipment you can't hurt anything alright so show start up show running about this one show interfaces Wow this command is going to give you great details about the health and statistics of your interfaces I would never run it that way you'd be there forever what we tend to do is we do show interface and then give the name of the one you want to look at maybe it's fastethernet 0/0 you the information for Fast Ethernet 0 / 2 you could do show interface fastethernet 0/1 it to look at that information for interface 14 so awesome stuff by the way does this switch have a MAC address table I hope it does that's what a layer 2 switch is supposed to do and if you just want to see the dynamic entries that have been learned in that MAC address table do show MAC address table dynamic and look at this the switch is doing thank goodness what we hired it to do in our network it is dynamic learning the MAC addresses of the network devices that live off of those ports

Channel: StormWind Studios

Views: 738,149

Keywords: cisco systems, switching, basics, configuration, catalyst, ios, software

Id: mQ4WQrjmHpc

Length: 28min 31sec (1711 seconds)

Published: Thu Jun 06 2013