Abstract: A method for automatically distributing IP address, which is applied to a switch in communication with all clients having a MAC address and a network segment where all clients are located, comprises automatic issues or assignments of an IP address in response to ARP requests and detecting within a first waiting period which is of random length for each client whether an IP address assigned to a client conflicts with that of other clients. The assigned IP address of the client is unchanged when the IP address of the client does not conflict with other client but, subject to a MAC condition, is released for future non-use after a second random waiting time in case of IP address conflicts between clients. An IP address automatic distribution system and a client are also disclosed.