Basic Switch Port Configuration

hi my name is Chris Albertson and I'm gonna go over some real simple of switchboard settings on a layer to switch today and it's gonna be some very very basic stuff basically what we want to do today is I'm going to show you how to tell which module how to access the module - which how to identify which module is identified by which number and then once we do that we're going to I'm going to show you how to directly get to that interface to make any configuration changes or to use interface range command or to configure and use a interface range macro and then once we do that we'll go over how to turn a port on and off with a shut in those shut commands how to set a port description how to set the ports duplex and speed and then lastly we'll follow up with some air disabled options basically how to see what air disabled options are configured on your switch how to change those air disabled options and then how to view the stats on the interface to verify various things like I look at the counters verify duplex and speed look at that MAC address look at the air status we can also see the interface IP address also if one is configured typically a switch port interface would not have a IP address assigned to it because that was that's a layer 3 boundary an IP address but on layer 3 switches it's possible to set an IP address on the interface what we're looking at here on the screen is I have a 2950 and we're just gonna go over things that I mentioned here on this 2950 what we're seeing here is I have errors or console logging enabled I'll disable that here in a moment but I just wanted to show you how to do that and and basically we're at the the user mode I'm gonna assume that you already know how to change between user privilege exec mode and configuration mode but as you can see this is the user mode and if I wanted to get to privilege the exec mode I would just simply type enable and now I'm in verbs exec mode which is the pound sign right here let's take a look at what interface we have on this device basically those are the fast ethernet interfaces we have on here as I mentioned module numbers I wanted to go over that with you here we see that we have 24 interfaces available to us one VLAN interface which is a default which we'll go over in a later video but this first number is the module this second number is the interface for a switch like a 2950 that does not have any ability to plug in any modules all the interfaces are going to be 0 and those are the interfaces that are in in the chassis now if we have the ability to plug in modules like this example here here's an example of a 29 39 25 it has ability to plug in 4 modules into this device if we were to have a module plugged in here that would be what say we had a 24 port module plugged into this spot right here and it was a fast ethernet just like we had gone to seen on the other fan interface it was FA 0 1 if we wanted to get to the first interface on this module would be fa fa 1/1 and this would be fa 2/1 and fa 3 / 1 & 4 so the first number is the module number and then the interface so we go back here module one two three and four and then the interface now if this was also a stackable switch would say this is the first switch in a stack and we have another switch underneath it and we wanted to and and those two switches acted as one switch which is possible we would say switch one or switch to module 1 and then interface 1 so it could be FA 1 and then module 1 and an interface one if that's hopefully that's clear so in that case the first number out of the three would be switch second number be module at their number would be interface so what we want to do now is show you how to directly configure a interface and we can do that we're back here on our switch would go to config terminal and then I would type in the interface I want to configure which let's go ahead and configure fastethernet 0/1 now one thing you'll notice that you can abbreviate a lot of commands because some people put config T some people use compte you can put interface fastethernet 0/1 or you can use int fa0 one which would be the exact same result but I usually like to use the whole command to get used to it because when you take some certification exams with Cisco they don't allow you to use abbreviations so it's best to use the whole command until you're comfortable with it and then you can bereave e8 so if you run into a certification that doesn't allow you to Brie v8 you're not totally just lost so now we're in configuration interface mode then we're going to configure or actually we could configure from here fastethernet 0/1 and that's a way to directly get to the center face and currently this interface is up now if I wanted to configure a range of interfaces or access a range of interfaces for configuration I can do that with the interface range command it would be interface range and then fastethernet 0/1 through let's say 10 now in this case I'm in configuration interface range mode any changes that I make will be applied to interface FA 0 1 through FA 0 10 if I wanted to I would say configure all of the odd interfaces from 1 to 9 I can set up the reins or you know use a configuration interface range for that to the interface ranged FA 0 / 1 FA 0 / 3 FA 0 / 5 FA 0 / 7 FA 0 / 9 now that's given me the ability to configure all of those interfaces and only those interfaces and as you can tell having to type that end over and over again if you're going to do a lot of configurations on a regular basis could be quite tedious so you can define a macro and we'll do that here define interface range and we're going to name the macro and this is case sensitive so we're going to name it odd and this macro is going to be FA 0 / 1 FA 0 / 3 FA 0 / oops 0 0 / 5a 0 / 7 FA 0 / 9 and oops yeah it likes to have spaces on each side of the commissary and now that interface macro is defined and this interface macro was saved in your running configuration we look at our running configuration OCR here is an example of a console logging message and if you don't like to see these console logging messages you can go no logging actually have to do that from configuration mode no logging console so basically all those logs are now turned off and they go straight to the login they don't get mirrored on the console so we don't have to see that so let's go back to show run and we'll see our macro in here and our macro is right here define interface range odd and it is these interfaces now if anytime anytime we want to make changes to those interfaces we can use this macro which we will do now let's go ahead and change the description of all of those interfaces to odd so we would go interface range macro and this is case sensitive so I'll do lower cases to show you ah okay so it says macro odd is not defined let's go ahead and make this upper case now we're configure in that range of interfaces and we're going to set the description for all these interfaces to odd and let's go ahead and shut these interfaces down basically shut turns off the interface if we wanted to turn it back on those should would turn that interface back on now we see those interface descriptions are now odd and those interfaces that we were we shut down or all admin down now actually interface to is previously I've been down but yeah all those are admin down now now if I wanted to turn them back on 50 your face range macro necro odd no show now we see that there all along except for two which I had turned off already so as I'm sure you can see using a macro here could be very useful if you had a random set my seemingly random set of interfaces that you had to shut down and those shut down or something on a regular basis you know you could type in that macro that you didn't have defined here or you know you could go and type this missing again and over and over every time you did it which really I would make the macro I think it would be much easier so now as we had said previously we were going to talk about no shuttin shot which we did so in the description and then we're going to show you how to set the duplex on speed of an interface now the reason you might set the duplex and speed manually is because you have a legacy device on your network that can't auto negotiate duplex of speed that's not very common anymore and setting the duplex on speed could actually cause issues on your network if it's not set properly so again we would go to configuration terminal from privileged exec mode and then we could go to the interface we wanted to mess with let's go to interface FA 0 2 and we could set the duplex and we'll look at the options we have spot right duplex question mark will give you the options that could follow after that command and typically if you are at the end of your options let's say the CR there means a carriage return so what that means is basically you have the command completed you can the enter key to enter your command now from here oops see we did not have a CR in our list of options and we didn't pick anything we went to duplex and hit enter and we got the incomplete command because we have to do blue duplex and one of these three options now an interface is honest which is by default set to you Auto negotiate the duplex to the connection but like I said if you have some reason to set the duplex to half or full to force it to that you can do so with this command and that would force the interface to be in either full duplex or half duplex basically rendering the auto negation autonegotiation ability of the interface useless or not you supposed to adjust basically turning it off so let's go duplex full if I were to show run interface fastethernet 0 2 which was the one we were just on I would see that now I have duplex set to fool now if I wanted to change that back to auto negotiate I can do it no duplex fool or a duplex auto now we see that duplex full option is gone because we are Auto negotiating I could do the same thing with speed and again show you we didn't have a carriage return here as an option so I put speed with no follow-up switches their options and it came back with an incomplete command so I have to use 10 100 or auto this is just a fast ethernet switch so 100 megabits is the fastest speed but if you had a gigabit switch you would have to actually have a thousand option in here also so if I was to set the speed to 10 now I can see the speed is set to 10 now let's go ahead and put that back to you Auto negotiate I can do that with no speed ten or speed Auto now what we're gonna do next is go over the oops sorry err disabled options for a switch originally Cisco had created the air disabled feature to handle specialized collision situations like excessive collisions or late collisions basically late collisions were caused by the media basically a layer 1 cabling being without being outside of specifications like being too long or damaged or having duplex mismatches on the interface around the cabling interfaces so that was the first introduction of artists there they're disabled detection by Cisco later on they added more options to detect for and we can see that when we go to our switch here and let's go ahead and do a show err disable detect this is going to show us all the types of error disabled err disable detection that our switch is currently detecting for you can look at basically all of these on my website too for some descriptions I'm not going to go over each one here but by default a switch automatically detects for all possible errors and if we wanted to change any of this error detection would say we wanted to disable any of that particular any of those options there that wouldn't be possible for all options but if we go to config mode now one thing you remember like I said all error options are on you see they're all enabled right here so we're gonna have to use the no command to turn any of these off so if we ever go to we'd have to go no err disable detect cause and if we do the question mark here we will see that these are the only options that we can turn off and if we were to pick all it would only turn all of these off so let's go ahead and turn off a loopback cause look back and now we see loopback is disabled and in order to re-enable Lubeck whoops ok config terminal we're gonna do not the no option this time we're going to go err disable detect cause and now we see that it is rien a boleyn see that if you wanted to disable all of these except for loopback it would be easy to go no air disable detect cause all and then air disabled cause loop back and that would disable all these and in turn loop back at back on ok now typically a port will shut an interface down when an air condition one of these air conditions occurs which would cause you to have to go to the switch or log into the switch somehow correct the condition that caused the air disabled and then manually put the port down by doing a shut and then a no shut and that would clear the condition or you can configure this to happen automatically and we'll show you how to do that go back to configuration terminal and we're gonna go air disable recovery loops recovery cause now what we can do here is we can cause our switch to auto recover from any of these conditions so let's say if you want to cause it to auto recovery from every possible condition there you can pick all or you can pick bpdu guard or whatever so let's in this case what's pick um loop back now we also want to tell it how often to do this recovery so we have the interval option we can use and from here we can tell it we want to do this every 30 seconds or every day so this is 60 I'm sorry 86,400 seconds is 24 hours and that's 30 seconds you know to have a switch continuously trying to connect an air or correct an air every 30 seconds may not be feasible if you don't realize that there's a problem right away it would cause the switch to keep trying this over and over again but I think a day would be a little bit extreme so we're just we're going to go 30 seconds here I'm trying to remember I think to see that period of time we can go show air disabled recovery and it shows us here that we are automatically recovering from loopback conditions only and we're gonna do that every 30 seconds now this is a global the time here is global so this time applies to everything so if you wanted to auto recover from BPT bpdu guard conditions every 30 seconds and loop acts every 60 seconds that wouldn't be possible they all have to be done at the same same interval now let's go ahead and look at an interface real quick now this is a layer two interface and I'll show you how to tell that here in a little bit but it is it's the layer to switch port interface and we said we see that it is up and the line protocol is up now there's first up is saying us that we have layer 1 connectivity basically we have a cable plugged in and we know that there is voltage on that cable that aligned protocol that's the layer two so we know we have layer 1 connectivity and layer 2 connectivity and this is the MAC address to this particular port MTU size the reliability of the connection now this 255 / 255 that is a best reliability if we have less reliability you know we'd have like 50 overt or 50 / 255 now this is the load transmit and receive loads which basically there's hardly anything going across this interface and we have the full duplex which is was Auto negotiated the speed which was Auto negotiated the type of cabling which is cat5 twisted pair and then we have the stats for the last five minutes and the totals now let's go ahead and switch to another switch that I have in production and we'll look at the stats on phaser one here now this is also was up and up now this particular interface has an IP address it's a layer 3 interface and we can see that it had some traffic going it's not a lot I don't have a lot of traffic going over this interface right now and we can see that the total number of packets that were output and the last time that the the these counters were cleared is right here which I've never cleared these counters since the thing is since this router has been up now I have another interface on here that's currently err disabled well it will be err disabled here in a moment just one so my previous err disabled condition had cleared itself so I went ahead and made a new air condition and I have an air disabled port if a0 to right now we see that with the show interface status command and if I wanted to look at just that interface a show interface status and then I can get there disabled and this will show me all the air disabled interfaces and where air disabled because we have a bpdu guard condition and then we'll go over that later in our spanning tree video but that's how I can tell that this port is there disabled and I could also do that by showing interface if a 0 2 and up here at the top it says that we are air disabled and in this case the the router has automatically shut down this port because of this condition and I can also see this if I was a deal with show log at the end of my log here I would see that we had a spanning tree air disabled could here before we had we have been disabled and we were covered but now we're currently disabled so I think that brings us to the end of our video so if you have any questions you can again see me at my my website there you put comments there or you can post them on the YouTube page or this videos have it if you post them here I'll see him a lot quicker alright and hope you enjoy the video all right bye-bye

Channel: Chris Albertsen

Views: 44,539

Rating: 4.807229 out of 5

Keywords: Cisco Switch Configuration, Network Switch (Product Category)

Id: 3yGmSznWjyM

Length: 28min 14sec (1694 seconds)

Published: Wed Aug 13 2014