One of the challenges faced by network management systems is the increasing need for consistent management of physical network equipment. We propose a solution where equipment is modelled using a dedicated Domain Specific Language (DSL) enriched with the power of logic-based reasoning services. This enables us to define a rich layer of semantics on top of the structural description of the devices. This way, the configuration related constraints are expressed declaratively, in a platform independent manner, and are managed in an integrated way with the structural model. The information kept in the model can then be used on runtime to give guidance to the system user.