Cisco Networking: Command Buffer Basics

By Edward Tetz from Cisco Networking All-in-One For Dummies

If you type the same Cisco networking commands again and again, you can make use of the command buffer, or terminal history. By default the command buffer holds ten lines, but it can be reconfigured with the Privileged EXEC mode terminal history size 10 command. To see the contents of the buffer, use the following command:

Router(config)#do show history
  hostname Router
  int fastEthernet 0/0
  ip address 192.168.1.2 255.255.255.0
  exit
  int fastEthernet 0/1
  ip address 10.0.0.1 255.0.0.0
  exit
  do show history

The Privileged EXEC mode and Global Configuration mode each have their own command buffers, so if you make configuration changes and want to see them, use the do command. Remember, show is not an available command in Global Configuration mode. Instead, use the do command to tell the IOS to run the show command from Privileged EXEC mode rather than Global Configuration mode.

There are only a few Privileged EXEC mode commands that you can run with the do command.

If you see a command in the command buffer that you want to run again, you can copy and paste it back into your terminal application. This process varies depending on the application you use.

You can quickly review what commands are in the terminal buffer by using the up- or down-arrow key on your keyboard. Use the up-arrow key to scroll through your last commands; if you go too far, use the down-arrow key to go back.