Beginning with the IOS 12.3, privileged-exec mode commands (such as show running-configuration, show interface status, etc.) can be executed within the global configuration mode and its submodes. This allows you to execute privileged-exec mode commands without needing to exit the current configuration mode. Here is an example that explains the usefulness of this feature:
In the example above you can see that we’re currently in the interface mode. We want to get more information about the interface with the show interface Fa0/1 command, but we got an error because the command is not available in this mode. However, if we use the do keyword in front of the command, the command will succeed:
The command was now executed because of the do keyword. Notice that we’re still in the interface submode and we can continue with the interface configuration.