用途說明
ssh命令是Linux下常用的遠程登錄客戶端工具，它常用來替代telnet，因為telnet采用明文傳輸，安全性差，而ssh采用安全傳輸機制，是遠程訪問的首選。
常用方式
格式：ssh <host>
使用SSH遠程登錄主機<host>，端口為22。用戶為當前登錄用戶。
格式：ssh -p <port> <host>
格式：ssh <host> -p <port>
使用SSH遠程登錄主機<host>，端口為<port>。用戶為當前登錄用戶。
格式：ssh -l <user> <host>
格式：ssh <user>@<host>
使用SSH遠程登錄主機<host>，端口為22。用戶為<user>。
格式：ssh -p <port> -l <user> <host>
格式：ssh -p <port> <user>@<host>
使用SSH遠程登錄主機<host>，端口為<port>。用戶為<user>。
要注意的是sftp工具的端口指定方式是
sftp -oPort=<port> <host>
使用sftp訪問主機<host>，端口為<port>
怎樣更改sshd的服務端口？
由於OpenSSH也會有安全問題，有時候又不想更新到最新版本，那麼常見的提高系統安全性的方法就是修改sshd的服務端口，打開/etc/ssh/sshd_config，找到#Port 22那行，改成別的端口，比如Port 2622。然後重新加載sshd配置，即執行service sshd reload。
使用示例
示例一
[[email protected] ~]# ssh 192.168.1.181
The authenticity of host '192.168.1.181 (192.168.1.181)' can't be established.
RSA key fingerprint is 5e:bf:a3:bf:a5:40:58:02:ce:00:55:53:50:f8:73:46.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.1.181' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sat Mar 26 11:41:14 2011 from cvsbank
[root@linuxidc root]# exit
logout
Connection to 192.168.1.181 closed.
[[email protected] ~]#
[[email protected] ~]# ssh 192.168.1.181
[email protected]'s password:
Last login: Sun Apr 17 11:45:54 2011 from 192.168.1.191
[root@linuxidc root]# exit
logout
Connection to 192.168.1.181 closed.
[[email protected] ~]#
示例二
[[email protected] ~]# ssh -p 18622 192.168.1.186
The authenticity of host '192.168.1.186 (192.168.1.186)' can't be established.
RSA key fingerprint is 70:99:59:b2:f3:55:f9:fd:7d:a8:3b:76:d0:63:f7:32.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.1.186' (RSA) to the list of known hosts.
[email protected]'s password:
[root@web186 root]# exit
logout
Connection to 192.168.1.186 closed.
[[email protected] ~]#