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Appendix A      Cisco IOS Basic Skills
Understanding Command Modes
Table A-2 Command Modes Summary
Mode Access Method PromptExit/Entrance 
Method About this Mode
User EXEC Begin a session with 
your router.
Router>To exit router 
session, enter the 
logout command. Use this mode to:
Change terminal 
settings.
Perform basic tests.
Display system 
information....

  
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Appendix A      Cisco IOS Basic Skills
Getting Help
Getting Help
You can use the question mark (?) and arrow keys to help you enter commands.
For a list of available commands at that command mode, enter a question mark:
router> ?
access-enableCreate a temporary access-list entry
access-profileApply user-profile to interface
clearReset functions
...
To complete a...

  
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Enable Secret and Enable Passwords
For a list of command variables, enter the command followed by a space and a question mark:
router> show ?
clock Display the system clock
dialerDialer parameters and statistics
exceptionexception information
...
To redisplay a command you previously entered, press the up-arrow key. You can...

  
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Using Commands
Step 4Enter the configure terminal command to enter global configuration mode, indicated by (config)# in 
the prompt: 
router# configure terminal
router (config)#
You can now make changes to your router configuration.
Using Commands
This section provides some tips about entering Cisco IOS commands at the command-line...

  
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Saving Configuration Changes
Saving Configuration Changes
You need to enter the copy running-config startup-config command to save your configuration changes 
to nonvolatile RAM (NVRAM) so that they are not lost if there is a system reload or power outage. This 
example shows how to use this command to save your changes:
router #...

  
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Where to Go Next
If you want to disable a feature, enter the keyword no before the command; for example, no ip 
routing.
Save your configuration changes to NVRAM so that they are not lost if there is a system reload or 
power outage.
Where to Go Next
To configure your router, go to Chapter 3, “Basic Router Configuration,” and...

  
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APPENDIXB
ROM Monitor
This appendix describes the ROM monitor (also called the bootstrap program). The ROM monitor 
firmware runs when the router is powered up or reset. The firmware helps to initialize the processor 
hardware and boot the operating system software. You can use the ROM monitor to perform certain 
configuration tasks, such as recovering a lost password...

  
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Appendix B      ROM Monitor
ROM Monitor Commands
TimesaverBreak (system interrupt) is always enabled for 60 seconds after the router reboots, regardless of whether 
it is set to on or off in the configuration register. During this 60-second window, you can break to the 
ROM monitor prompt by pressing the Break key. 
ROM Monitor Commands
Enter ? or help at the ROM...

  
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Appendix B      ROM Monitor
Command Descriptions
Commands are case sensitive. You can halt any command by pressing the Break key on a terminal. If 
you are using a PC, most terminal emulation programs halt a command when you press the Ctrl and the 
Break keys at the same time. If you are using another type of terminal emulator or terminal emulation 
software, refer to...

  
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Appendix B      ROM Monitor
Disaster Recovery with TFTP Download
This section describes how to load a Cisco IOS software image from a remote TFTP server to the router 
Flash memory. Use the tftpdnld command only for disaster recovery because it erases all existing data 
in Flash memory before downloading a new software image to the router.
TFTP Download Command...