Methods and devices are disclosed for changing the configuration state of a network device such as a router, a switch or a similar device without the need for a person to interpret a textual diff. According to some aspects of the invention, a programmatic diff file that includes the output of two comparisons is used as an input file to a program that “rolls back” the current configuration state to a prior configuration state. According to other aspects of the invention, the output of a single comparison is input to an “incremental diff” process, which adds new commands to a configuration state. According to preferred aspects of the invention, the output files generated by the comparison processes preserve the hierarchical context of each command in a programmatic format that is usable as direct input by the network device or by another device (such as a host controlled by a network administrator) that performs the incremental diff.