Networking

Is automatically upgrading the Cisco IOS really possible?

Cisco's latest IOS offers a number of commands that allow you to configure the router to automatically download the IOS from Cisco's Web site. Find out what the new Cisco IOS Auto-Upgrade Manager (AUM) has to offer.

Your Windows PC receives updates automatically, right? Wouldn't it be nice to be able to automatically upgrade your Cisco routers?

Sure, there have been some tools that do this in the past. But most of us just do our TFTPs, router by router. That works great for a few routers, but once you have more than 50, it turns into not a lot of fun.

However, Cisco now offers an auto-upgrade feature in its IOS that could help make your life easier. Let's check it out.

How do you upgrade routers now?

If you're like me, you probably just upgrade a router using a TFTP server. My favorite has always been Tftpd32.exe because it's tiny, easy, and free.

However, I've also used IOSLoaderPro in the past. This is a very cool 750-KB application from VitalTech Group, which also makes IOSHunter, RouterConfigurator, IPCalculator, and WatchUp (not to be confused with WhatsUp).

IOSLoaderPro runs for about $40, but you can try it for free for 14 days. It can back up all files from the router's flash, back up the configuration, restore erased files, and more. I've found it to be a very useful application.

Meet the Cisco IOS Auto-Upgrade Manager

Although IOSLoaderPro offers some features over standard TFTP, it still isn't as easy as Windows Update. But do you want your routers to automatically update anyway? It really depends on the situation. You don't want the entire network going down in the middle of the day because of an automatic update and reboot of all your routers and switches, but it's still nice to have options.

Cisco's latest IOS offers a number of commands that allow you to configure the router to automatically download the IOS from Cisco's Web site or another server you specify. Not only can the router download the update, reload the IOS, and reboot, it can even e-mail you when it's finished.

While most of you are probably hesitant to "set it and forget it," let's take a closer look before we completely dismiss the idea. Dubbed the Cisco IOS Auto-Upgrade Manager (AUM), this new feature is available on Cisco 1800, 2800, and 3800 series routers running 12.4(15)T. Of course, the irony of AUM is that you must first manually upgrade your routers before they can even support the new IOS.

How AUM works

AUM's purpose is to make the IOS upgrade process easier for both novice and experienced network administrators. That's why AUM can upgrade a router by interactively asking the admin questions, or the admin can initiate it in a single line.

In general, here's what AUM can do:

  • Obtain the upgrade from a FTP server, TFTP server, or directly from Cisco over the Internet.
  • Download the upgrade using SSL, if needed, to secure the transfer.
  • Store the image in flash.
  • Perform a disk cleanup if there's not enough space.
  • Schedule the upgrade.
  • Perform a warm boot (i.e., decompress the image and load it into RAM before the router reboots).
  • Roll back to the old software if the process fails.
  • Log the configuration lines that were incompatible with the new IOS.
  • E-mail the status of the upgrade — success or failure.

As you can see, the AUM does a lot of things. In fact, Cisco offers a workflow diagram that depicts the process that AUM goes through to successfully upgrade your Cisco IOS.

While you must first configure a number of prerequisite to use AUM, there are two primary IOS commands that you need to know:

Router# autoupgrade
Router# upgrade automatic getversion

In my opinion, AUM is very configurable, and it seems that Cisco made every attempt to make it safe and reliable. To learn more about AUM, check out Cisco's product release page and its Configuring the Cisco IOS Auto-Upgrade Manager documentation.

Summary

Automatically upgrading your Cisco routers isn't too far off. Sometime soon, you'll no longer have to spend evenings upgrading your routers. All you'll have to do is to sit back and relax — and wait for the text message, page, or e-mail telling you that all your routers have successfully upgraded!

David Davis has worked in the IT industry for more than 12 years and holds several certifications, including CCIE, MCSE+I, CISSP, CCNA, CCDA, and CCNP. He currently manages a group of systems/network administrators for a privately owned retail company and performs networking/systems consulting on a part-time basis.

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