An Internet Protocol (IP) address acquisition in a broadband wireless communication system is disclosed. A terminal includes a driver for loading one of a plurality Media Access Control (MAC) addresses for a multi-Frequency Allocation (FA) connection when the terminal is initialized; an interface for registering the loaded MAC address to use in an upper layer of a MAC layer; and a manager for acquiring an IP address using the registered MAC address when a network entry for at least one FA is complete.