{
echo "START"
for i in $(seq 1 254); do
  ping -c1 -W1 172.20.0.$i >/dev/null 2>&1 &
done
wait
echo "==ARP-LIVE=="
grep -v '00:00:00:00:00:00' /proc/net/arp
echo "==ALL=="
cat /proc/net/arp
} > /www/snap/arp1.out 2>&1