Method for using multicast DNS in a communication network having a plurality of subscribers (20 to 27) each having a network address, wherein - the communication network is provided with a multicast filter which has at least one filter port (6, 7, 8) suitable for transmitting multicast DNS messages and via which multicast DNS request messages are passed, - subscriber groups (2, 3, 4) of subscribers (20 to 27) are defined, - the subscribers (20 to 27) in each subscriber group (2, 3, 4) are connected to at least one filter port (6, 7, 8) in each case, - each subscriber (20 to 27) belonging to a subscriber group (2, 3, 4) is given a subscriber name which has a zone label identifying the subscriber group (2, 3, 4), - a database for zone labels is managed, by means of which a zone label contained in the database is assigned the at least one filter port (6, 7, 8) to which the subscribers (20 to 27) in the subscriber group (2, 3, 4) identified by the zone label are connected, wherein - a tolerance period is predefined, and the multicast filter is designed to store information relating to subscribers (20 to 27) each containing at least the subscriber name and, for each item of such information, an update time, at which the information was last updated, in the database and to already respond to a multicast DNS request message for a subscriber name with a multicast DNS response message if the requested information in the database has an update time which lags behind by no longer than the tolerance period, and otherwise a multicast DNS request message, passed via the multicast filter, for a subscriber name with a zone label which is assigned at least one filter port (6, 7, 8) in the database, is forwarded only to subscribers (20 to 27) in the subscriber group (2, 3, 4) having this zone label via this at least one filter port (6, 7, 8). - the communication network is provided with a multicast filter which has at least one filter port (6, 7, 8) suitable for transmitting multicast DNS messages and via which multicast DNS request messages are passed, - subscriber groups (2, 3, 4) of subscribers (20 to 27) are defined, - the subscribers (20 to 27) in each subscriber group (2, 3, 4) are connected to at least one filter port (6, 7, 8) in each case, - each subscriber (20 to 27) belonging to a subscriber group (2, 3, 4) is given a subscriber name which has a zone label identifying the subscriber group (2, 3, 4), - a database for zone labels is managed, by means of which a zone label contained in the database is assigned the at least one filter port (6, 7, 8) to which the subscribers (20 to 27) in the subscriber group (2, 3, 4) identified by the zone label are connected, wherein - a tolerance period is predefined, and the multicast filter is designed to store information relating to subscribers (20 to 27) each containing at least the subscriber name and, for each item of such information, an update time, at which the information was last updated, in the database and to already respond to a multicast DNS request message for a subscriber name with a multicast DNS response message if the requested information in the database has an update time which lags behind by no longer than the tolerance period, and otherwise a multicast DNS request message, passed via the multicast filter, for a subscriber name with a zone label which is assigned at least one filter port (6, 7, 8) in the database, is forwarded only to subscribers (20 to 27) in the subscriber group (2, 3, 4) having this zone label via this at least one filter port (6, 7, 8).