The 2.05.09.xx firmware line is recommended as the general code-of-choice, compatible with all three generations of hardware, when closed-loop stacking and redundant management are not required. See ent14241 for additional information.
PATCH releases are here for your convenience. A Patch contains a specific set of feature corrections that are outlined in the Release Notes for that Patch. A Patch has not been subjected to the standard regression tests to which a Generally Avaliable Release or Maintenance Release would be subjected. A Patch has been tested to confirm the feature is functioning as expected. Unless otherwise stated in the Patch Release Notes, a Patch has all the inherited restrictions and limitaions as the code upon which it was based. Please read all the Release Notes prior to installation of any Patch in your production network. Please report any undocumented issues you find using the normal technical support procedures found in your product documentation.
Instructions for upgrading firmware on most Enterasys devices: