Cisco Router Show Commands Cheat Sheet

Cisco routers run an operating system, called IOS. Like any operating system, IOS includes a command language to enable equipment owners to retrieve information and change the device’s settings. One of the most powerful commands in IOS is show. This command retrieves information. This guide gives you information on the most important data that you can get out of your router with the show command.

Help

Before we discuss the main subject of this guide, there is one very helpful little tool in the Cisco operating system that you should know about. This is the help command, which is typed as ?. If you type ? at the command prompt, you will get a list of all available commands in the operating system. If you type a command and follow it with ? (like show ?) you will get an explanation of the parameters for that command. Some commands have several different purposes that are tailored by a second word. You can get specific help for that branch of command by typing ? after it. For example, show ip ? will show you all of the information options that relate to IP data.

Cisco show command cheat sheet

The following table lists the show commands that you are most likely to use in your day-to-day administration tasks.

Show optionMeaning
show interfaces Displays information of all interfaces in the chassis or one specified interface
show interfaces switchportDisplays the status of a switching (non routing) port
show interfaces trunkDisplays information on the interface-trunk
show ip interfaceDisplays statuses of all IPv4 interfaces, add brief to get a summary
show ipv6 interfaceDisplays statuses of all IPv6 interfaces, add brief to get a summary
show ip trafficDisplays statistics on IP traffic
show ip routeDisplays the IPv4 routing table of the router
show ipv6 routeDisplays the IPv6 routing table of the router
show ip wccpDisplays information related to the Web Cache Control Protocol
show controllers Displays clock rate and connected cable type for interface hardware element
show controllers tech-supportDisplays general information about a VIP card for problem reporting
show hardwareDisplays the hardware specific information for the router
show clockDisplays the system clock of the router
show environmentDisplays temperature, voltage, and blower information
show hostsDisplays the configured hostnames and their corresponding IP addresses of the router
show usersDisplays all users connected to the router
show inventoryDisplays the product inventory listing and UDI of all Cisco products installed on the router
show file systemsLists available file systems
show disk:Displays file system information for the disk at the given slot number
show processes detailed Displays detailed information about all current processes or a specified process
show processes cpuDisplays all processes and their CPU utilization
show processes memory Displays the amount of memory used by each system process or a specified process
show historyDisplays command line history
show flashDisplays information about Flash memory
show versionDisplays information about loaded Cisco IOS software
show mac-address tableDisplays the MAC address table
show arpDisplays the ARP table of the router address to MAC address mappings
show protocols Displays status of configured Layer 3 protocols; both parameters are optional
show loggingDisplays the state of syslog and the contents of the standard system logging buffer.
show startup-configDisplays configuration saved in NVRAM
show running-configDisplays configuration currently running in RAM
show spanning-treeDisplays information about the spanning tree state
show vlanDisplays VLAN information
show contextDisplays context data
show cefDisplays information about packets sent by Cisco Express Forwarding
show clnsDisplays information on connectionless-mode network service packets that have passed through the router
show cdp neighborsDisplays information of connected routers found through the Cisco Discovery Protocol
show system jumbomtuDisplays the system maximum transmission unit size
show currentDisplays the current Multiple Spanning Tree Protocol settings and allows you to edit them
show pendingDisplays the candidate Multiple Spanning Tree Protocol settings and allows you to edit them

Further reading

There are a lot more show commands than those listed in this guide. For a definitive list, take a look at the Cisco IOS Configuration Fundamentals Command Reference. You can also read our Cisco Discovery Protocol tutorial.