Cisco Systems Cisco 12816 Manuale Utente

You can use the method that suits your operating style and your knowledge of 
network configuration requirements.

Whether you use the setup command facility or global configuration mode to 
configure the router to operate in your networking environment, be sure you know 
the:

Interfaces the router has.

Protocols the router is routing.

Network addresses for the protocols being configured.

Password scheme for your environment.

Cisco IOS software provides a command line interface that allows you to 
configure and manage your router. If you are not familiar with the Cisco IOS 
command line interface, you should read the “Using the Command Line 
Interface” chapter in the Configuration Fundamentals Configuration Guide. This 
section discusses the different command modes, context-sensitive help, and 
editing features of the interface.

The Cisco IOS user interface is organized into several different modes. The 
available commands depend on which mode you are currently in. Entering a 
question mark (?) at the system prompt displays a list of commands available for 
the current command mode.

When you start a session on the router, you begin in user EXEC mode. Only a 
limited subset of the commands are available in EXEC mode. In order to have 
access to all of the commands, you must enter privileged EXEC mode which 
normally requires a password. From privileged EXEC mode, you can enter any 
EXEC command or enter global configuration mode. Most of the EXEC 
commands are 1-time commands, such as show commands, that show the current 
configuration status, and clear commands, that clear counters or interfaces. The 
EXEC commands are not saved across reboots of the router.