Part 2:
Introduction to IOS:
IOS is the internetwork Operating system that provides an operating system for cisco routers

IOS allows you to change what the router does.
IOS also runs on CISCO managed switches, and this will also aloow us to change what they do as well.

How does CISCO router number their interfaces, this is because we can have several of the same kind of interface in the same router.

CISCO equipment has a numbering scheme based on either fixed configuration or the position of an interface card in a slot

Even though we can look at alot of things when we're in privileged exec mode, we still cant change much. TO CHANGE THINGS, WE NEED TO SWITCH TO CONFIGURATION MODE.

BASIC CONFIGURATION COMMANDS

Hostname

If you type "hostname testing" at the configuration prompt, you'll change the router's name. What has happened to the configuration prompt?

it has changed from router15 to testing

Router

This is a router, so why don't we try turning routing on? (This isn't going to work properly but it will illustrate the point.) Type router rip at the configuration prompt.

What has happened to the configuration prompt?
It has changed to testing(config-router)

Type exit, then change the hostname back to what it was when you started. Then type CTRL-Z or exit then [enter] to exit configuration mode.

What does the prompt look like now?
It looks the same as previous now