关于tcpdump命令抓包时网络接口的查询与指定

-D
--list-interfaces
       Print  the  list  of  the network interfaces available on the system and on which tcpdump can capture packets.
       For each network interface, a number and an interface name, possibly followed by a  text  description  of  the
       interface,  is  printed.  The interface name or the number can be supplied to the -i flag to specify an inter‐
       face on which to capture.

       This can be useful on systems that don't have a command to list them (e.g., Windows systems, or  UNIX  systems
       lacking  ifconfig -a); the number can be useful on Windows 2000 and later systems, where the interface name is
       a somewhat complex string.

       The -D flag will not be supported if tcpdump was built with  an  older  version  of  libpcap  that  lacks  the
       pcap_findalldevs() function.