{
for net in 17 18 19; do
  echo "== scan 172.$net.0.0/24 :30010 =="
  for i in $(seq 1 254); do
    (timeout 1 bash -c "echo >/dev/tcp/172.$net.0.$i/30010" 2>/dev/null && echo "OPEN 172.$net.0.$i") &
  done
  wait
  echo "== ARP 172.$net =="
  grep "172.$net\." /proc/net/arp
done
echo "== DONE =="
} > /www/snap/r4.txt 2>&1