遇到這樣的問題可能有這幾個情況:
1、在安裝centos的時候沒安裝ssh
2、sshd_config與ssh_config配置問題
3、IP問題
4、防火墻問題
一、安裝CentOS SSH
yum install ssh
二、啟動SSH
service sshd start
三、進入系統文件etc/ssh/sshd_config文件配置
1.vi /etc/ssh/sshd_config 將PermitRootLogin的注釋取消，或者將no改為yes。
2.service sshd restart
3.setup命令進入將防火墻關閉。
四、進入系統文件 /etc/ssh/ssh_config文件配置
在終端下面輸入：vi /etc/ssh/ssh_config
去掉Port 22前面的#號
Port 22
五、配置IP
ifconfig eth0 192.168.121.11
This error indicates that SSH Secure Shell for Workstations cannot establish a connection to the remote host computer. There are several reasons that might cause this situation.
It may be that you have simply made a typing mistake, and there is an error in the name of the remote host computer. In this case you should also receive an error stating that the host is unknown.
Check that you have defined the correct port number for the connection. The port can be changed on the Connection page of the Settings dialog.
There may be problems with the configuration or physical setup of the network connection. Verify that other network connections are functioning.
This problem may also arise if your local system is protected by a firewall and the firewall has not been properly configured. If you suspect that this is the case, ask your local system administrator to reconfigure the firewall.
There may also be a temporary problem with the remote host computer. If this is the case, you should wait for a while and try to connect again later. Contact the administrator of the remote host computer for additional information.
這個錯誤表示工作站的SSH安全Shell不能建立到遠程主機電腦的連接。有幾個原因可能導致這種情況。
這可能是因為你只是做了一個打字錯誤，有一個錯誤在遠程主機的計算機名稱。在這種情況下，你也應該會收到一個錯誤，說明該主機是未知。
檢查是否已定義為連接正確的端口號。可以改變端口上的連接“頁面設置”對話框。
有可能是與網絡連接的配置或物理安裝的問題。確認網絡連接是否正常。
如果您的本地系統防火墻和防火墻沒有正確配置的保護，這個問題也可能出現。如果懷疑是這種情況，請問您的本地系統管理員重新配置防火墻。
也有可能是一個與遠程主機上的臨時問題。如果是這樣的話，你應該等待一段時間，并嘗試再次連接后。更多信息，遠程主機的計算機管理員聯系。
圖解：
