ssh-keygen -f "/root/.ssh/known_hosts" -R 172.21.136.107
ssh username@172.21.136.107
if 出现 permission denied please try again. ssh
要修改root的ssh权限，即修改 /etc/ssh/sshd_config文件中
PermitRootLogin without-password
改为 PermitRootLogin yes
并在该行下，添加 AllowUsers root username