public DHCPMessage(){
  initialize();
  this.destination_IP=BROADCAST_ADDR;
  this.gPort=SERVER_PORT;
}

public DHCPMessage ( ) { initialize ( ) ; this . destination_IP = BROADCAST_ADDR ; this . gPort = SERVER_PORT ; }
creates empty dhcpmessage object , initializes the object , sets the host to the broadcast address , the local subnet , binds to the default server port .
