A method of establishing and maintaining a consistent configuration state of a first processor, running on a first version of operating software, and a second processor, running on a second version of operating software, is described. The method involves determining a current configuration state of the first processor, where the configuration state comprises a list of configuration commands. The method also involves performing a syntax check for each command in the current configuration, using the second processor and the second version of operating software, with the syntax check resulting in a pass or a fail result. For every command which results in a fail result, an entry is added to a mismatched configuration list (MCL). Embodiments of this invention can be utilized to keep the configurations consistent during an upgrade or downgrade of the operating software.