ETHER_IS_MULTICAST
#define ETHER_IS_MULTICAST(addr) (*(addr) & 0x01) /* is address mcast/bcast? */
#define ETHER_IS_MULTICAST(addr) (*(addr) & 0x01) /* is address mcast/bcast? */
#define ETHER_IS_MULTICAST(addr) (((addr)[0] & 0x01) != 0)