Cisco Networking: Privileged EXEC Operating Mode
You need to use Privileged EXEC mode if you want to really have update access to a Cisco network system,. To enter this mode from the User EXEC mode, issue the enable command, which prompts you for a password, if configured.
As the mode name suggests, this mode has extra privileges to allow you to make major changes to the system or to enter Configuration mode. When you are in Privileged EXEC mode, your command prompt resembles the following (this is the hostname, which by default is the name of the device, but could be anything else):
The hash/pound sign (#) denotes that you are in the Privileged EXEC mode. Some of the commands that are available include these commands that you should find in all devices, be they routers, switches, or firewalls
cd: Change the current directory. Routers and switches have several file systems, including flash, nvram, system, and null.
clear: Resets functions operating on the device. There are many values that are totaled for reporting that can be reset this way. You can also reset many system-wide configuration values.
clock: Allows you to change the system clock.
copy: Copy a file from one location to another. The location could be another local file system or a remote file system, such as a Trivial File Transfer Protocol (TFTP) server.
debug: Turn on debug logging. This can be done for a specific interface or software component, or for all functions. This places a load on the device if the debugging level is too high and generates an incredible level of messaging on the console screen.
delete: Removes a file from a file system.
dir: Displays the list of files in the current directory.
disable: Reverts the current session back to User EXEC mode and disables the privileged commands.
erase: Removes all files in a file system. This is similar to an OS-level format command.
exit: Exits from Privileged EXEC mode.
no: Reverses a previously issued command. For example, debug all turns on all possible debugging, whereas no debug all turns off all possible debugging. Just about every command that can be issued can be reversed with the no command.
ping: Sends ping or ICMP echo request packets to a remote IP host, such as a switch or router.
pwd: Displays what the current file system directory is.
reload: Restarts the device. This restart can be immediate or scheduled for the future. The reload command can also be used to cancel a scheduled reload.
send: Sends a message to specific or all connected users. This is useful if you are about to perform certain maintenance tasks, such as rebooting the device.
show: Displays configuration information. This is typically configuration information that is running, but it could also be used to view the startup configuration.
systat: Displays information regarding management connections to this device.
telnet: Opens a Telnet connection to a remote device, such as a router or switch.
test: Tests subsystems, memory, and interfaces as part of your diagnostic or troubleshooting process.
traceroute: Traces a route to a destination displaying connectivity results along the path.
undebug: Disables debug commands that were set. This is an alternative to using the no command to perform these functions.
write: Copies information in the running-config buffer to another location, such as memory, a TFTP server, or to the virtual terminal (vty) or console connection.