IFF_ALLMULTI      Receive all multicast packets.        接收所有多播数据包。
IFF_AUTOMEDIA     Auto media selection active.          自动媒体选择激活。
IFF_BROADCAST     Valid broadcast address set.          有效的广播地址集。
IFF_DEBUG         Internal debugging flag.              内部调试标志。
IFF_DORMANT       Driver signals dormant (since Linux 2.6.17)   驱动程序信号休眠（从Linux 2.6.17开始）
IFF_DYNAMIC       The addresses are lost when the interface goes down. 当接口关闭时，地址将丢失。
IFF_ECHO          Echo sent packets (since Linux 2.6.25)    Echo发送的数据包（从Linux 2.6.25开始）
IFF_LOOPBACK      Interface is a loopback interface.   接口是一个环回接口。
IFF_LOWER_UP      Driver signals L1 up (since Linux 2.6.17)    驱动程序信号L1向上（从Linux 2.6.17开始）
IFF_MASTER        Master of a load balancing bundle.  负载平衡捆绑包的主人。
IFF_MULTICAST     Supports multicast    支持多播
IFF_NOARP         No arp protocol, L2 destination address not set.   没有arp协议，未设置二级目标地址。
IFF_NOTRAILERS    Avoid use of trailers.     
IFF_POINTOPOINT   Interface is a point-to-point link.
IFF_PORTSEL       Is able to select media type via ifmap.
IFF_PROMISC       Interface is in promiscuous mode. 
IFF_RUNNING       Resources allocated.
IFF_SLAVE         Slave of a load balancing bundle.
IFF_UP            Interface is running.