A communication device of an industrial automation system and method for configuring the communication device, wherein a communication network address assigned to the communication device is independently generated from at least one prefix communicated via router advertisement messages by at least one router assigned within a subnetwork and from a device-specific interface identifier, where the communication device interrogates at at least one server of a name service system, in accordance with a name resolution protocol, which communication network addresses are assigned to its communication device name, the communication network addresses interrogated at the at least one server of the name service system are checked with regard to correspondence to the prefix, and where the communication device assigns to itself only those communication network addresses interrogated at the server of the name service system which have a correspondence to the prefix communicated by the router.