5 Cisco IOS Commands Every Network Admin Should KnowBy David Davis
There are 5 commands that every Cisco network administrator should know. These are core administration commands that will help you to really know what is going on.
If you are new to Cisco networking, these are good commands to memorize. On the other hand, even if you are a seasoned administrator, you may find a few commands in this article on which you could use a refresher. We will start the list at the bottom and move to #1.
IOS Command #5 – show interfaces
It is important to know what interfaces are on your router, important statistics about those interfaces, and whether they are up or down. The show interfaces command is a very verbose command that provides a lot of output. You may have to pick through that output to find what you are looking for; just about everything to do with interfaces is shown in the output from this command. For example: errors on an interface, bandwidth utilization, and interface speed.
This command can be abbreviated as sh int.
IOS Command #4 – copy running-config startup-config
Once you make your configuration changes, you need to save those changes. This command copies the configuration in RAM that you have been modifying to the configuration in flash. By copying it to flash, it will be saved when the router is powered off and restarted.
A shortcut for this command is wr (short for write memory).
IOS Command #3 – show ip route
Once you know that your interfaces are up and you have saved your configuration, you need to know if you have full network reach-ability. In other words, are your routing protocols working? What static routes have you entered? With the show ip route command, you can find out.
This command can be abbreviated sh ip ro.
IOS Command #2 – show ip interface brief
We saw the show interfaces command. This is the show ip interface brief command. So, you are only showing information about the interfaces as it pertains to the IP protocol. You are also asking for brief output. This command gives you the best summary of the status and IP addresses of your interfaces.
This command can be abbreviated sh ip int brie
And the #1 most important command that every network administrator should know is…
IOS Command #1 – show running-config
With the show running-config command, you see the entire router’s config. It’s that simple. You see the IP addresses, interfaces, passwords (that are in clear text), routing protocols, and other settings.
This command can be abbreviated sh ru or wr t.
Using the Cisco IOS is all about knowing what command to type in order to do what you need to do. The 5 commands shown in this article are just a few of the thousands of possible Cisco IOS commands. However, these commands are some of the core commands that every network administrator should know.
About the Author
David Davis is a CCIE, vExpert, VCP5, and VCAP-DCA. He has been in the IT industry for 20+ years and is the author of hundreds of articles and videos. He has created over 10 TrainSignal video training courses including the numerous courses that make up the best-selling VMware vSphere video training library.
Author's Website: http://www.vmwarevideos.com/