Cisco Help and Editing
Enter ? at any prompt to see a complete listing of available commands that can be used at the prompt level. You can also do partial a word to see available commands that start with letters before ? (e.g. s?, cl?, eth?).
When entering commands, you don't have to complete the entire word just enough to make it recognizable to the IOS from any other command. Example: instead of using the show command, you can use sh in place of show and it will work the same.
The ? can also be used to show the next step in the command. If you type a partial command and press the [Tab] key, the command is completed for you automatically.
Router_2(config)# int [Tab]
Router_2(config)# interface ?
Async Async interface
BVI Bridge-Group Virtual Interface
Dialer Dialer interface
Ethernet IEEE 802.3
Group-Async Async Group interface
Lex Lex interface
Loopback Loopback interface
Null Null interface
Port-channel Ethernet Channel of interfaces
Tunnel Tunnel interface
Virtual-Template Virtual Template interface
Virtual-TokenRing Virtual TokenRing
Router_2(config)# interface ethernet ?
<0-0> Ethernet interface number
Router_2(config)# interface ethernet 0
Use the [spacebar] to scroll another page if available commands is longer than one page, use the [enter] key to scroll one line at a time. If help page is scrolled, press any key to return to the command line.
Command Line Editing Commands
||Moves cursor to beginning of the line.
||Moves cursor to end of line.
||Moves back one character.
||Moves back one word.
||Moves forward one character.
||Moves forward one word.
||Deletes a single character at the cursor.
||Deletes a single character.
||Redisplays the command prompt and command line.
||Erases a line.
||Erases a word.
||Ends Configuration mode and returns to EXEC.
||Finishes typing a command for you.
Router Command History
|Ctrl+P or Up arrow
||Shows last command entered.
|Ctlr+N or Down arrow
||Shows previous commands entered.
||Shows last 10 commands entered by default.
||Shows terminal configurations and history buffer size.
|terminal history size [0-256]
||Changes buffer size (max 256).
To see how long a router has been up, how it was restarted, the IOS version, number of Interfaces, memory, and config-register setting
use the command show version from privileged EXEC mode.