}
do
j=7
tag=1
while [ $j -ge 0 ]
do
k=$((2**$j))
if [ $(( $i & $k )) -eq $k ]; then
if [ $tag -eq 1 ]; then
(( n += 1 ))
else
echo -e "\n$2 is a bad netamsk with holes\n"
exit
fi
else
tag=0
fi
(( j -= 1 ))
done
done
for i in 0 1 2 3
do
a=$a${a:+.}$((${ip} & ${mask}))
b=$b${b:+.}$((${ip} | (${mask} ^ 255)))
done