Cisco Networking: Command Help

When you are connected to a Cisco network device with an open console connection, help is available. You are staring at this friendly command prompt, or something similar:

Router>

So now what? Well, you can ask the IOS for help. Type a question mark after Router>, and the IOS displays a list of commands that are possible at that level.

Router>?
EXEC commands:
  access-enable    Create a temporary Access-List entry
  access-profile   Apply user-profile to interface
  clear            Reset functions
  connect          Open a terminal connection
  crypto           Crypto
  disable          Turn off privileged commands
  disconnect       Disconnect an existing network connection
  enable           Turn on privileged commands
  exit             Exit from the EXEC
  help             Description of the interactive help system
  lock             Lock the terminal
  login            Log in as a particular user
  logout           Exit from the EXEC
  modemui          Start a modem-like user interface
  mrinfo           Request neighbor and version information from a multicast
                   router
  mstat            Show statistics after multiple multicast traceroutes
  mtrace           Trace reverse multicast path from destination to source
  name-connection  Name an existing network connection
  pad              Open a X.29 PAD connection
  ping             Send echo messages
 --More-

 

When the --More- text is displayed at the bottom of a page (see the preceding code), you can press Enter to advance the list by one line or press the spacebar to advance by one screen. If you prefer to start typing one of the commands, you can hit just about any key to exit from the --More- listing and type your command.

Other times you may start typing the letters of a command but you cannot remember what the actual command is. Anytime you type the command, you can add a question mark to the end of it to see what commands could be completed. Here is an example in Privileged EXEC mode:

Router#c?
call   ccm-manager  cd         clear
clock  cns          configure  connect
copy   crypt

dummies

Source:http://www.dummies.com/how-to/content/cisco-networking-command-help.html