How to read ASA software version?

Let’s check examples below:




Software version – 8.4(2)

Train – 8.4

Maintenance – (2)

Interim -N/A




Software version – 8.4(7)5

Train – 8.4

Maintenance – (7)

Interim – 4 (4th interim of 8.4(7))


“Interim” relases are built more often then “maintenance” and contain fixes for specific bugs found in earlier maintenance release. They are built and delivered by Cisco to their customer until next “maintenance” software is published.

“Interim” releases are not so deep tested as “maintenance” and should be used only if your environment is affected by specific bug which is solved by interim release.

In all other cases we should use the latest stable maintenance software.


dzbanek 2014-04-15