SSH统计登录失败IP和次数

10 * * * * /root/sshLoginRestrictions.sh  > /dev/null 2>&1 & 

sshLoginRestrictions.sh

#! /bin/bash
cat /var/log/secure|awk '/Failed/{print $(NF-3)}'|sort|uniq -c|awk '{print $2"="$1;}' > /tmp/black.list
for i in `cat /tmp/black.list`
do
ip=`echo $i |awk -F= '{print $1}'`
num=`echo $i|awk -F= '{print $2}'`
if [ $num -gt 20 ]; then
grep $ip /etc/hosts.deny > /dev/null
if [ $? -gt 0 ];then
echo "sshd:$ip:deny" >> /etc/hosts.deny
fi
fi
done

解除IP限制：将限制IP加到白名单/etc/hosts.allow 

sshd:黑名单IP:allow