/* sort -k4,4g */
IFF_UP		(1 << 0)
IFF_BROADCAST	(1 << 1)
IFF_DEBUG	(1 << 2)
IFF_LOOPBACK	(1 << 3)
IFF_POINTOPOINT	(1 << 4)
IFF_NOTRAILERS	(1 << 5)
IFF_RUNNING	(1 << 6)
IFF_NOARP	(1 << 7)
IFF_PROMISC	(1 << 8)
IFF_ALLMULTI	(1 << 9)
IFF_MASTER	(1 << 10)
IFF_SLAVE	(1 << 11)
IFF_MULTICAST	(1 << 12)
IFF_PORTSEL	(1 << 13)
IFF_AUTOMEDIA	(1 << 14)
IFF_DYNAMIC	(1 << 15)
IFF_LOWER_UP	(1 << 16)
IFF_DORMANT	(1 << 17)
IFF_ECHO	(1 << 18)