extern void set_ipv4_address(uint32_t own_ip);
extern uint32_t get_ipv4_address(void);
extern void set_ipv4_multicast(uint32_t multicast_ip);
extern void set_ipv4_address(uint32_t own_ip);
extern uint32_t get_ipv4_address(void);
extern void set_ipv4_multicast(uint32_t multicast_ip);