On occasion I get asked if there is a location on CCO that lists the software deferral notices for all Cisco IOS images in order to determine if the software release they are running is affected by a notice. The answer is yes and you can find this information typically located in the release notes, well just to clarify, you can find a link to the deferral notices in the release notes. The direct link is located here:

Deferral Advisories for Cisco IOS Software (CCO Login Required)

But going back to the release notes lets look at a few examples and the reason I want to show this is that the single greatest location for information is ALWAYS contained in the release notes. I find the release notes to be more informative than the documentation yet each has their own purpose….If you want to avoid RPE’s (Resume Producing Events) in your environment, please read the release notes first. I can’t tell you the number of issues I deal with week to week that could have been avoided by simply reading the release notes first.

For instance lets look @ 12.4T code. In the release notes for 12.4T code there is a direct link to the deferral section:

Deferrals

Cisco IOS software images are subject to deferral. Cisco recommends that you view the deferral notices at the following location to determine if your software release is affected:

http://www.cisco.com/public/sw-center/sw-ios-advisories.shtml

The same holds true for IOS XE, take a look @ the release notes for RLS 2.1 code and there is a direct link to the deferral section:

Deferrals

Cisco IOS software images are subject to deferral. Cisco recommends that you view the deferral notices at the following location to determine if your software release is affected:

http://www.cisco.com/public/sw-center/sw-ios-advisories.shtml