Now in a previous video, I showed you how to connect to the console of a Cisco router or switch.
But now let's actually build a basic topology using Cisco routers and switches.
So in this topology, I'm gonna add a 4321 router to my topology.
I'll add another one and then let's add a 3650 switch to the topology to physically cable these devices.
I'm gonna use a straight-through copper cable from the first Gigabit Ethernet interface of the router
to the first gigabit Ethernet interface of the switch.
Notice how the switches start at 1 0 1 here.
But the router started gigabit.
0 0 0 now just to be consistent.
I like to say Cisco is inconsistent so depends on device to device the interface numbers really depend
on the devices.
So you just have to look at the physical devices.
Generally a switch starts at Interface one, router started interface zero as a general rule but things
do vary sometimes.
I'll connect this port to the second interface on the switch.
Now the interfaces are down at the moment because the switch needs power.
So I'm gonna drag a power supply into the switch and what should happen is these should eventually change
colour but I can verify that things are working by clicking on the switch and going to CLI.
And what you'll notice is the switch has now booted.
Now these will still be down because what I need to do is enable the ports on the routers, another difference
between switches and routers is switch interfaces by default come up generally.
So as soon as you power the switch on all the interfaces or enable but routing interfaces all by default
disabled or shut down you need to enable those interfaces by using the no shutdown command.
So on a router, we would need to no shut the interface but before we get there I'd like to take you
through this initial configuration dialog.
Generally we would type
NO but I'm just gonna do it once.
I'm going to type YES here so that we can go through the initial configuration dialog and what it's
going to ask me is a whole bunch of questions, like Do we want to enter basic management set up, I'm going
to say yes we're asked, What is the name of the switch I'm going to say S1 for whatever name I want to
use, then we're asked to set a password on the switch.
I'm gonna say Cisco, now a secret password uses what's called a hash.
It's a type of encryption but it's not encryption it's a hash.
But basically the password is encrypted so it's not easy to guess or see in the running configuration
or the active configuration of the device an older password was the enable password.
I'll set this to Cisco1 generally you shouldn't use that old password a VTY line or virtual terminal
password is a way to Telnet or SSH to a device remotely.
So if you want to be able to SSH or Telnet to the device you need to have a password configured so I'm gonna
set that to Cisco.
Do we want to configure simple network management protocol?
I'm going to say NO.
The problem here is it's asking you a whole bunch of questions.
In some ways it's easier just to bypass all of this and just configure what you want on the switch rather
than having to answer this quiz if you like.
Now we're told that here is a list of interfaces and we can see a bunch of interfaces on the switch.
We're now asked, Enter interface name used to connect to the management network.
From the above interface summary.
So I'm gonna say gigabit
1 0 1 for argument's sake, Enter interface name to connect to the management network from the above interface
summary.
So I'm gonna try this one and paste that, we're asked do we want to configure an IP address for this interface.
I'm going to say no, we're now asked, Do you want to go to the IOS prompt without saving this conflict.
And here's the config that it's generated so it's created a configuration for us including notice the
secret password being encrypted or hashed to use the correct term.
Here's the enable password.
Here's the VTY password.
Here's the hostname and it's added some other configuration like no shutting this interface.
We can return back to the setup without saving this config and go through this nightmare again or save
this configuration to NV RAM and exit.
I'm gonna just say, skip all of this and press enter.
So seriously for the real world don't use that but I would suggest that you go through this just once
or twice using packet tracers that you can see what it's like but generally don't waste your time with
this is not important for the exam and it's not important for the real world
So I wouldn't waste a lot of time going through this, go through it once, if you just want to see what
it does but otherwise don't bother, so going back to our topology.
Interfaces are still down because on the router, I'm going to go to the CLI and I'm going to bypass
that initial configuration dialog and press Enter to get started, now to configure the router the first
thing I need to do is go to enable mode so I've typed enable and I'm using the shorthand here and what
I need to do is configure the interface on the router
Now we don't see the interfaces because in packet tracer I've gone to options, preferences and I disabled
this option show port labels in logical workspace, so I'll enable that now.
And as you can see now interface gigabit 0 0 0 on the router is connected to interface gigabit 1 0
1 on the switch, so on the router, I can type CONF T to go to global configuration mode and then type
INT which is shorthand for interface I'll press tab then I need to choose my interface which is gigabit
so I'm going to use G tab to auto-complete and then I need to put the interface numbering now you'd
need to know this.
So I'm going to use gigabit 0 0 0 so 0/0/0 again the interface numbers depend on the device.
So you just have to see what's on your device.
I'll give you a short cut to help you if you're not sure.
Very good command.
So I'm gonna type end to go back to privilege mode.
This command show IP interface brief, will save you a lot of time.
So show IP interface brief will show me the interfaces on the router.
We'll talk about V LAN interfaces later.
But notice gigabit 0 0 0 and gigabit.
0 0 1 are the interfaces on the router and I'm connected to the first gigabit interface.
0 0 0.
So, again to configure the right and I'll go right out of the router so we can start again.
So press enter.
I'm in user mode type enable to go to privilege mode or enable mode, CONF T to go to global configuration
mode.
I'm gonna use shortcuts now interface gigabit 0 0 0 you could have typed that out.
Interface gigabit 0 slash 0 slash 0.
I'm just using shorthand here or shortcut commands IP question mark.
Address will allow me to configure an address on the device I'll put two S's there just to make sure
that the full command is displayed.
I'll use an IP address like this 10.1.1.1 space question mark what subnet mask.
Am I going to use, I'm going to use 2 5 5 2 5 5 2 5 5 0 and press Enter now hopefully you understand about
IP addresses.
If you don't please review the IP addressing section of this course I explain
IP addresses in a lot of detail.
Now again this interface is by default shut.
Notice red, I'm going to type no shut, which is shorthand for no shutdown.
Notice as soon as I did that it went green and I'm told that the interface has come up type exit to
go to global configuration mode.
Let's give this router a name, so I'm gonna type host tab for hostname, R1 so the routers name is
R1 type end, and I should save my configuration by using the command copy running config startup
config and press enter to save the routers configuration.
So what I've done is I've configured an IP address on this router let's do something similar
on the second router, Now you might see that the names are not as I configured them so let's change that
to R1.
Let's change this to be S1 and let's change this to be R2
that's just a visual name in Packet Tracer so I'll click on the router go to CLI and I'm gonna
bypass this initial configuration dialog because it's just a nightmare.
I'm in user mode at the moment.
Notice the greater than sign type in, type E N press tab.
Takes me to privilege or enable mode.
Notice the hash, type C O N F as in configure, press tab there T tab so configure terminal.
Let's give the router hostname so H O S T if I press question mark I can see the available command, I'll
press tab now R2
So that's the name of the router
I'm gonna type I N T tab interface.
Question mark.
I can see a list of available commands but I can't type fast Ethernet 0 0 0 because that interface doesn't
exist on the router, I've gotta use the right interface numbers.
Interface gigabit 0 0 0 0.
Once again I could look in packet tracer to see the interface number or if I type
end once again use the command show IP interface brief to see a list of available interfaces on the
router.
Okay so CONF T interface G tab 0 0 0 0.
Enter, no shutdown to enable the interface IP address 10.1.1.2
In this example slash 24 mask type END WR, old command but much quicker way to save the config of
the router.
Notice Green, the side is green.
The side is orange because a switch uses what's called spanning tree to stop loops.
So we've got to wait 30 seconds for that to go green before we can ping from one side to the other.
It's gone green now.
So on router 1, I should be able to ping router 2, ping once again is basically sending a message saying
Are you there.
And then the device replies back saying, Yes I'm here.
If it works this is a timeout.
Ping requires that the response comes back in a certain amount of time.
And in this case it didn't so it timed out and then we get some successful responses on Router 2
I could ping router 1 and that succeeds.
So I've now built a very basic network of a switch and two routers.
Can you do the same.
Please create a network like this in packet tracer using a switch and two routers and configure the
routers with IP addresses and get them to ping each other.
Best way to learn networking is just to do it.
build topologies and try things in this course there are many topologies that I'm going to use to test
your knowledge and help you learn these technologies.
So start with a very basic topology like this and see if you can get it working.