密码登录
Ubuntu 系统的默认用户名是 ubuntu，并在安装过程中默认不设置 root 帐户和密码。您如有需要，可在设置中开启允许 root 用户登录。具体操作步骤如下：
首先另辟路径登上你的基于Ubuntu的服务器
执行命令，设置root密码sudo passwd root
输入密码，重复输入密码，返回passwd: password updated successfully说明root密码设置成功
打开sshd_config配置文件，路径/etc/ssh/sshd_config，具体的ssd_config解析
找到# Authentication:修改PermitRootLogin yes
# Authentication:#LoginGraceTime 2m#PermitRootLogin prohibit-password# 禁止密码登录，只允许通过密钥登陆PermitRootLogin yes#StrictModes yes#MaxAuthTries 6#MaxSessions 10
修改PasswordAuthentication参数为yes，没有就添加
# To disable tunneled clear text passwords, change to no here!PasswordAuthentication yes#PermitEmptyPasswords no
重启ssh服务，sudo service ssh restart。或者重启服务器，或sudo systemctl restart sshd
然后就可以通过cmd窗口命令
ssh root@公网ip或域名#但是域名得提前解析到公网ip
如果出现以下WARNNING，就把C:\\Users\\andya/.ssh/known_hosts:1下的known_hosts这个文件删掉
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!Someone could be eavesdropping on you right now (man-in-the-middle attack)!It is also possible that a host key has just been changed.The fingerprint for the ECDSA key sent by the remote host isSHA256:W02kdKGXXmOYxdbdWRS4lj6GU0B+wBaL6VjmoiD6t6c.Please contact your system administrator.Add correct host key in C:\\Users\\andya/.ssh/known_hosts to get rid of this message.Offending ECDSA key in C:\\Users\\andya/.ssh/known_hosts:1#这个路径！！！ECDSA host key for yanghe.life has changed and you have requested strict checking.Host key verification failed.
