Examining the show commands

Examining the show commands
3.1.4 This page will introduce some show commands. Many of these commands can be used to examine the contents of files in the router and for troubleshooting. In both privileged EXEC and user EXEC modes, the command show ? provides a list of available show commands. The list is considerably longer in privileged EXEC mode than it is in user EXEC mode.


Students should learn the functions of the following commands:

• show interfaces – Displays statistics for all interfaces on a router. To view the statistics for a specific interface, enter the show interfaces command followed by the specific interface slot/port number. This is shown in the following example:

Router#show interfaces serial 0/1

• show controllers serial - Displays information that is specific to the interface hardware. This command must also include the port or slot/port number of the serial interface. For example:

Router#show controllers serial 0/1

• show clock - Shows the time set in the router
• show hosts - Displays a cached list of host names and addresses
• show users - Displays all users who are connected to the router
• show history - Displays a history of commands that have been entered
• show flash - Displays information about flash memory and what IOS files are stored there
• show version - Displays information about the currently loaded software version along with hardware and device information.
• show arp - Displays the ARP table of the router
• show protocols - Displays the global and interface-specific status of any configured Layer 3 protocols
• show startup-config - Displays the saved configuration located in NVRAM
• show running-config - Displays the contents of the currently running configuration file or the configuration for a specific interface, or map class information.

The Lab Activities on this page will teach students how to view router configurations with the show commands. The next page will explain how a serial interface is configured.