When you first start a Cisco router, there is some initial configuration. The router software will ask for a minimum set of details through a dialogue called optional setup. Startup routines Cisco IOS software are designed to initialize the router operations.
For this, the start-up routines should do the following:
• Make sure the router has verified hardware (POST).
• Locate and load the Cisco IOS software that uses the router for your operating system.
• Locate and apply the setup instructions for the specific attributes of the router, the protocol functions and interface addresses.
The router makes sure that the hardware has been verified. When a Cisco router is turned on, do some tests at baseline (POST). During this self test, the router runs a series of tests to verify the basic operation of the CPU, memory and interface circuitry. After verifying that the hardware has been tested, the router comes with software initialization. Setup mode is the way you start a router is not configured to boot.
You can exit this mode not responding to the initial question.
Would you like to enter the initial configuration dialog? [Yes]: No
Would you like to terminate autoinstall? [Yes]: INTRO
From the router command line starts at the user EXEC mode, tasks that can run in this mode are just a check and not to allow configuration changes. In privileged EXEC mode perform tasks typical configuration.
Router>
Router> enable
Router # disable
Router>
To switch privileged user to run the enable command to disable return. This is possible because no password is set; otherwise it would be required each time you happen to privileged mode.
Global mode and interface:
Router> enable
Router # configure terminal
Router (config) # interface ethernet 0
Router (config-if) # exit
Router (config) # exit
Router #
To switch between global privileged must enter the configure terminal command to switch between global to run ethernet interface 0, in this case we have chosen the ethernet 0. To return back one more way to use the exit or Ctrl + Z will take you directly to privileged mode.