A method for setting a host address in an Internet protocol based communication system, includes the steps of allowing a router to create a shorter label than a network prefix, the label being representative of the network prefix; allowing the router to incorporate the label instead of the network prefix in an RA (Router Advertisement) message and transmit the RA message to a host; allowing the host receiving the RA message to read the label and determine whether the read label matches a label in a prefix information table of the host; and, if the read label matches a label in the prefix information table, allowing the host to select and activate an interface ID (identifier) corresponding to the label of the prefix information table and acquire a global IPv6 (Internet Protocol, version 6) address corresponding to the activated interface ID as the host address.