Saturday, May 30, 2009

IOS Version Selection Tactics

The linked video provides guidance for optimal IOS version selection.
The large number of IOS versions makes choosing the best version for your router or switch difficult. You must pick the most reliable version which includes the features you need. Different IOS "packages" have different features. For example, the "LAN base" package includes basic switching code. "IP base" adds access-layer routing features (RIP and EIGRP-stub). "IP services" adds most layer-3 routing protocols (OSPF, EIGRP, BGP). "Advanced IP services" adds IS-IS and MPLS.
Picking a version also means picking one with recently introduced features you need. For example, 16-port 10-gigabit ethernet card support was added to the 6500 line in 12.2(33)SXH code. If you require that card, you cannot pick an older version, such as 12.2(18)SXF. The release notes include details on recently added features.
Finally, of all the versions that have the features you require, you want to pick the most stable version. That means picking a version that has been "rebuilt" with many bugfix-only releases. Picking 12.4(2)T, where 60 new features were just introduced, would be a bad idea. On the other hand, 12.4(23) (the lack of a letter means it is a mainline release) would be a good choice because that release has undergone dozens of releases since significant numbers of features were introduced.



Blogger Darrell Root said...

PDF version of presentation is at

May 30, 2009 at 9:30 PM  
Blogger Chris said...

If you are going to have an audio podcast I'd like to see it in additional to the video podcast and not in replacement of it. For myself I finder it easier to understand some of the concepts when there is a visual to go along with it.

June 1, 2009 at 3:35 PM  
Blogger Sean Branch said...


And thank you for sharing your knowledge. And thank you for your humility in admitting what you know and don't know.

I can tell that is why you are willing to share what you know with others. I commend you.

June 2, 2009 at 6:12 AM  
Blogger William said...

An audio podcast would be great, but as Chris said it would be beneficial to have it in addition to the video podcast. Perhaps use them in conjunction as a lecture/lab setup where you describe the technology in the audio and demonstrate it in the video?

There's my 2 cents, thanks for providing everyone with the opportunity to learn from your experience.

June 6, 2009 at 2:56 PM  
Blogger chrisv25 said...

Are there going to be anymore of these. I am really enjoying them. Thank you!

August 12, 2009 at 5:26 AM  

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