Method for automatic distribution of IP address, system and client using the same

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, isreleased 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. 种应用于与交换机通信且位于同网段内的多个客户端中的IP地址自动分配方法包括步骤：响应客户端的IP地址请求根据所述网段、其他客户端的IP地址及MAC地址确定在网段内且未被其他客户端使用的IP地址；将确定的IP地址与客户端的MAC地址绑定；侦测IP地址是否与其他客户端的IP地址冲突；在客户端的IP地址与其他客户端的IP地址不冲突时在第二随机等待时间后再次侦测客户端的IP地址是否与其他客户端的IP地址冲突；及在所述第二随机等待时间后再次侦测的客户端的IP地址与其他客户端的I