For example a typical cisco software relase is.. 12.2.25(EWA4).

My understanding is that 12 is the major release level, 2 is the minor release, 25 is the feature chain, and EWA4 is the patch level.

First are my assumptions correct above? Also what are others doing to stay current, I have heard 2 opinions, 1 you dont upgrade infrastructure, unless there is a patch/security issues/ feature you need becuase of availability, also I have heard the old you must be within 2 . release levels, does this mean 12.3 or 12.2.26 ? from 12.2.25? Appreciate any opinions.

Thanks.