DRAOn is a distributed reasoner which offers inference services for a network of OWL ontologies correlated by alignments. Reasoning with such networks of ontologies depends on the semantics we define for alignments with respect to ontologies. DRAOn supports two semantics for a network of ontolo- gies: the standard Description Logics (DL) semantics for non-distributed reason- ing, and the Integrated Distributed Description Logics (IDDL) semantics for dis- tributed reasoning. Unlike the DL semantics where alignments are considered as inter-ontology axioms, the IDDL semantics interprets alignments as correspon- dences enabling to propagate non-emptiness (always satisfiable) and unsatisfia- bility of atomic concepts from an ontology to another one. Consequently, this makes distributed reasoning for a network of ontologies possible since consis- tency of the whole network can be decided from consistency of each ontology with axioms built from alignments such that these axioms ensure just necessary propagations of knowledge.