In this example I'm connected to the console of a router when I type enable and then show version we
can see the version of Cisco Ioway running on the router.
So here's the short version.
C'mon Cisco IOS software that we're running is an 1841 version of software.
It's advanced enterprise software version 15 dot 1 4 and 8 release software.
See 2 What you'll notice is that a version of software is different to the software in Rome or read
only memory.
The system bootstrap a version here is Tove dot for the Shradha has been up for 5 hours and 40 minutes.
This is the version of operating system that the Rodda booted.
So the system image file is this file which is stored in Flash.
And that was loaded into memory Spaceballs shows me more information and I'll be able to see as an example
the amount of RAM in the router as well as the amount of ENVI ram before I look at that let's use the
C'mon show flash.
Notice this is the operating system that was loaded into RAM on the router.
So show flesh is similar to your hard drive.
We have the operating system as well as another file stored in Flash.
This is the size of flesh in bytes.
And this is how much has been used.
Here's another router
show flash here.
Shows us that a different version of operating system is found in the flash of this Rodda and other
files are also stored in the flash of the Rodda.
So this is very similar to a hard drive way.
Multiple files can be stored in flash as an example I could use a command show run pipe
and then redirect the output to flash and let's create a file called Show run test dot see if G.
Now when I use the C'mon show flash notice that file is available in Flash.
I've just copied the running config from RAM onto the flash drive.
On this router you can use the more command to view that file and what you'll notice is it shows us
that this is the current config at a specific time.
And that's because this is a copy of the running config on the router.
So the running config of the rod is stored in RAM so the show running config or show run command for
short shows us the size of the current configuration.
In other words the live config that's used by the router the shows start startup config shows start
config shows us the saved configuration stored in nv ram.
Notice the difference show startup shows us output using so many bytes out of so many bytes whereas
the show running config shows current config being so many bytes so just know the output when you use
show run you're going to see current config when you use the command show startup config will show start
you going to see so many parts out of so many pints.
Now we could use the Kamani re startup config and I was told that we are going to raise the nv ram file
system.
Do we want to continue.
I'm going to press enter to confirm that we want a raise the startup config.
So now when we use the command show startup config we are told that there is no startup config present
no startup configuration is stored in the RAM but the running config is still available on the router.
To save the configuration we would use the command copy running config startup config and that copies
the configuration from RAM to NV RAM.
So now when the top of the command shows startup config we see that a config is stored in NV ram that
config is not live.
So as an example if I created a loopback interface on this router and gave it a not-P address of something
like the following
show IP interface brief
shows me that that IP address is available now on the loopback interface on the router.
In other words the change was immediate.
Show run
shows us that a loopback interface.
In other words it happened immediately and was added to the running config.
Show startup config however doesn't show us the loopback interface changes are only written to the startup
config when you use the copy run startup config command or W-r for short.
So now when we look at the startup config
you'll notice that the loopback interface is configured as part of the startup config so the running
config is stored in RAM startup config is stored in NV RAM.
You can copy the startup config to NV RAM by using the command copy running config start up config.
That would be an exam on sir.
But for the real world you could simply use the command W-r.
You can also store files in Flash.
So as I demonstrated you could copy the running config on startup config to flash flash can store multiple
files as seen on this router but the primary file that flash is used for is the storing of the operating
system which is loaded into RAM when the router boots up.
Flash is nonvolatile.
In other words when the Rodda reboot the file is not lost but it will be removed from RAM when the Rodda
boots up the operating system is copied from flash to RAM so that it can be used in real time.
So let's look at the short version.
C'mon Again this shows this information once again about the uptime of the router the operating system
used how it was reloaded.
So this was normal reload and scrolling down.
We can see the amount of RAM available on the router.
Now that's in kilobytes to get the total RAM on the Rodda you need to add those two together.
So 2 3 9 6 1 6 plus 2 2 5 to 8.
That gives us the amount of RAM on the Radi So we need to divide by 1024.
And that shows us the amount of RAM on the Shradha it's got 256 mega ram this router however is using
a different version of operating system as we've seen and has a different amount of RAM so 2 3 3 4 7
2 plus 2 8 6 7 2 gives us that divide by 1024
well so gives us 256 mega RAM so you need to add these values together to work out the amount of RAM
in the router.
You'll notice that the nv ram value is a lot smaller than RAM only 191 kilobytes of envied RAM is available
whereas we've got 256 megabytes of RAM available.
This is the size of the compact flash.
On this router which is the same on this router.
Notice this router has two fast Ethan interfaces and two serial interfaces whereas this router has two
first Ethan interfaces one serial interface and one VPN module.
The interfaces on a router can very show IP interface brief
on the Shradha shows us the physical interfaces and once again show IP interface brief on this Shradha
shows us the interfaces on it which are different to Rodda one.