In a production environment is not up to view IP

#!/bin/bash
for i in `seq 1 254`
do
ping -c 1 192.168.64.$i > /dev/null 
if [ $? -eq 0 ];then
echo "192.168.64.$i存活"
else
echo "192.168.64.$i不存活" >>/root/a.txt
fi
done