Usage: ./bin/massdns [options] [domainlist]
  -b  --bindto             Bind to IP address and port. (Default: 0.0.0.0:0)
      --busy-poll          Use busy-wait polling instead of epoll.
  -c  --resolve-count      Number of resolves for a name before giving up. (Default: 50)
      --drop-group         Group to drop privileges to when running as root. (Default: nogroup)
      --drop-user          User to drop privileges to when running as root. (Default: nobody)
      --extended-input     Input names are followed by a space-separated list of resolvers.
                           These are used before falling back to the resolvers file.
      --filter             Only output packets with the specified response code.
      --flush              Flush the output file whenever a response was received.
  -h  --help               Show this help.
      --ignore             Do not output packets with the specified response code.
  -i  --interval           Interval in milliseconds to wait between multiple resolves of the same
                           domain. (Default: 500)
  -l  --error-log          Error log file path. (Default: /dev/stderr)
      --norecurse          Use non-recursive qu