ping一个网段内所有的IP

#!/usr/bin/bash
for ip in {1…254}
do
#read -p “请输入IP: " ip
ping -c1 -w0.1 10.18.42.$ip
if [ $?=0];thenecho"10.18.42.$ip is up” >> /tmp/
else
echo “10.18.42.$ip is down” >> /tmp/
fi
done