笔记：

groupadd 6lxx

useradd -s /bin/sh -d /home/6lxx -g 6lxx -m 6lxx

echo "KFi0Tu45"|passwd --stdin 6lxx

sed  -i '/^root/a\6lxx   ALL=(ALL)       ALL' /etc/sudoers

sed -i 's/#PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config

cat /etc/ssh/sshd_config|grep PermitRootLogin

###禁止root公钥登录

echo 0 > /root/.ssh/authorized_keys && chattr +i  /root/.ssh/authorized_keys

systemctl restart sshd

本文转自  674591788  51CTO博客，原文链接:http://blog.51cto.com/mrdeng/1887004