User guide

Internetworking Primer A-5
Cisco Internetwork Operating System
Cisco IOS
Normal operation of your access server requires the Cisco IOS image to be stored and
executing in Flash memory. A recommended setting for the configuration register value is
0x2102, which instructs the access server when it boots to do the following:
• Operate the image in Flash memory
• Ignore the Break key on the console port
• Attempt to load the Flash image only five times before reverting to boot ROM
Enter the command show version to display the Cisco IOS image and version that the
access server is running:
Router#show version
Cisco Internetwork Operating System Software
Cisco IOS (tm) 3000 Software (IGS-C-L), Version 10.2(6), RELEASE SOFTWARE
(fc2)
...
Command Modes
The Cisco IOS user interface provides several different command modes. Each command
mode provides a group of related commands. Table A-3 summarizes the key command
modes and their purpose.
Table A-3 Key Command Modes and Their Purpose
Command Mode Prompt Purpose How
User EXEC Router> User access First level accessed
Privileged EXEC Router# System administration Enter the command
enable
Configuration mode Router(config)# Modify configuration Enter the command
config
Setup Prompted dialog Create the initial
configuration
Enter the command
setup