subnet=$(./internal_ip.sh | cut -d '.' -f 1-3)
#echo $subnet
#for i in {1..10}; do ping -c 1 -W 1 $subnet.$i | echo ; done
#for i in `seq 1 254`; do ping -c 1 $subnet.$i | tr \\n ' ' | awk '/1 received/ {print $2}'; done
(prefix=$subnet && for i in `seq 254`; do (sleep 0.5 && ping -c1 -w1 $prefix.$i &> /dev/null && arp -n | awk ' /'$prefix'.'$i' / { print $1 " " $3 } ') & done; wait)