A method and apparatus for modifying the configuration of a network device, such as a router, using a two-stage configuration model is provided. A first request for a change in configuration of a network device is received. Configuration data that describes the change in configuration of the network device is stored in a buffer. A second request to modify the current operational state of the network device to reflect the configuration data stored in the buffer is received. An exclusive lock on the network device is obtained. The current operational state of the network device is modified to reflect the configuration data stored in the buffer. Multiple users may modify the network device without interfering with one another because conflicts are avoided through use of an exclusive lock. Requests of different management operations may be contained within XML documents that are transmitted from the client to the network device.