@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ 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 the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is 21:24:59:ba:53:d7:51:a2:12:13:40:09:53:03:5b:e6. Please contact your system administrator. Add correct host key in /home/cmccpay/.ssh/known_hosts to get rid of this message. Offending key in /home/cmccpay/.ssh/known_hosts:11 RSA host key for 10.202.76.27 has changed and you have requested strict checking. Host key verification failed.
出现该错误的解决方法：
1.因为在本地机器上曾经用SSH登录过这台远程计算机，因而留下了known_hosts的记录，在远程计算机重新安装系统后不能够通过鉴权。删除~/.ssh/known_hosts中对应的项目，问题获得解决。（很麻烦。。忽视之）
2.在客户端执行下述指令即可：$mv ~/.ssh/known_hosts /tmp （相对好一点，用过）
再次登录后会出现最初需要增加条目：
The authenticity of host '128.112.139.3 (128.112.139.3)' can't be established.
RSA key fingerprint is ce:78:c2:d5:26:11:42:cf:c6:e6:65:99:9c:60:51:34.
Are you sure you want to continue connecting (yes/no)? The authenticity of host '132.170.3.32 (132.170.3.32)' can't be established.
RSA key fingerprint is 91:14:9c:ea:e7:43:5d:8b:57:aa:51:57:e0:28:06:52.
Are you sure you want to continue connecting (yes/no)? yes
3. 配置文件进行配置，使出现“Warning: Host identification has changed!”时候可以自动更新~/.ssh/known_hosts中的相应条目，而不出现提示。（比较好！方便，无需后期处理）
OpenSSH 有三种配置方式：命令行参数、用户配置文件和系统级的配置文件（"/etc/ssh/ssh_config"）。命令行参数优先于配置文件，用户配置文件优先于系统配置文件。所有的命令行的参数都能在配置文件中设置。因为在安装的时候没有默认的用户配置文件，所以要把"/etc/ssh /ssh_config"拷贝并重新命名为"~/.ssh/config"。
（下一篇中具体介绍ssh的配置文件）
注意在配置文件~/.ssh/config中修改下面的内容：
Host *
GSSAPIAuthentication yes
BatchMode yes
StrictHostKeyChecking no