The first step the Rada performs a power on self test or post then it loads and runs the bootstrap code.
Thirdly it finds the Cisco Iowa software.
So the bootstrap code determines where the Cisco Iowas software is.
That should be run.
Normally this is located in flash memory but it could also be stored on a TFT server configuration register
and the configuration file determine with Cisco Iowas falls are located and which image file to use
if a Cisco Iowa image cannot be located a scaled down version of the Cisco Ioway is copied from Rome
into RAM.
That only applies however to older versions of Cisco routers in the past.
A mini operating system would be used but today the road will boot into run monitor mode.
If no Cisco is available after the bootstrap code is found the correct image it loads the image into
RAM and starts the sky with software.
Older rod is used to run the operating system from flash and memory.
But today once again the entire operating system is loaded into RAM.
Once the operating system is loaded the Radu will find the configuration which is typically stored in
nv ram so to load the startup config from nv ram and then apply it the startup config is loaded in RAM
and becomes the current all running config on the router.
The running configuration of Varada contains the IP addresses it determines which running protocols
need to be started.
Which passwords need to be configured and other characteristics of the router.
If no configuration file exists or the router enters the Setup Utility what Timpson.
Or to install of a configuration file from a TFT server.
The router then runs the configured Iowa software that's important to remember that Cisco Karaite the
Iowa software.
You can't change that but you can change how it's applied by changing the configuration on a router
in the same way as with Windows.
You can change the Windows operating system but you could change your desktop.
You could change the phones and other options in Windows.
The Cisco Iowa software can be manipulated through the configuration so you may decide to run the OSPF
routing protocol on one router but use the GOP on another router.
Your configuration determines the behavior of the Cisco Iowas on a router on those Fratta as an example.
They wrote it does have a startup config so show startup config shows us the configuration of this router
on this router.
We could raise the startup config
so now the shows start up c'mon show startup config.
C'mon shows us that there's no rodder configuration.
If we reload this router it will boot with no configuration and we should be prompted to enter the startup
wizard on this Shradha which does have a startup config.
So once again show start when we reload the router it should boot with the startup configuration applied
as the running config so shrouded doesn't have a startup config.
Whereas this router on the left does have a startup config so we should see the difference when they
boot up.
We can see the Rania's tryna get a configuration from a server.
So it's trying to boot and retrieve a configuration so it's sending a broadcast looking for a network
config this route is continuing to boot up
and notice a configuration has been applied.
The Rodda has a name.
And if we scroll up
we can see that various interfaces came up.
But in this case sure run shows us that a configuration has been applied.
So the configuration was copied from start up to running.
Ways and this Rodda the system configuration.
Dialog starts up and I pressed enter a few times and hence it was shown a few times and then I broke
out of the initial configuration dialog and noticed in this case shows start shows us that there's no
startup config and the router has a default configuration applied.
Now it did configure an IP address automatically on the serial interface using what's called slop.
That's why we were seeing this era where it was trying to connect to a TV B server and download a network
config as well as a Cisco net config file.
On some routers when there's a serial interface the router will automatically apply an IP address based
on the neighboring router to this interface and try and pull a config down from that neighboring router.
This router however has a configuration so we can see OSPF has been enabled.
There's a loopback IP address there's an IP address on the serial interface and any other configuration
would have been applied with this Rodda that doesn't have a startup config boots up.
No startup config is applied and it uses a default config and may do some automatic configuration or
use automated methods to try and find a configuration.
The moral of the story is as follows.
If there's no sort of config the router will typically boot up with some default values.
Such as having most interfaces shut down ways if a startup config is available in the router that startup
config will be applied.