|  | 3.1 | Router User Interface
| 3.1.6 | Using IOS command history
The user interface provides a history, or record, of commands that you have entered. This feature is particularly useful for recalling long or complex commands or entries. With the command history feature you can complete the following tasks: Set the command history buffer size. Recall commands. Disable the command history feature. By default, the command history is enabled and the system records 10 command lines in its history buffer. To change the number of command lines the system records during a terminal session, use the terminal history size or the history size command. The maximum number of commands is 256. To recall commands in the history buffer, beginning with the most recent command, press Ctrl-P or the up arrow key repeatedly to recall successively older commands. To return to more recent commands in the history buffer, after recalling commands with Ctrl-P or the up arrow, press Ctrl-N or the down arrow key repeatedly to recall successively more recent commands. When typing commands, as a shortcut, you may enter the unique characters for a command, press the Tab key, and the interface will finish the entry for you. The unique letters identify the command, the Tab key simply acknowledges visually that the router has understood the specific command that you intended. On most computers you may also have additional select and copy functions available. You can copy a previous command string and then paste or insert it as your current command entry, and press Return. You can use Ctrl-Z to back out of configuration mode.