Cloud server linux SSH cannot use xshell remote login: Could not connect to '192.168.xxx.xxx' (port 22): Connection failed.

Table of contents

1. Login

2. Process

3. Reuse the xshell remote connection successfully 

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When using centos7 to build a server, I don’t know why xshell suddenly can’t log in for no reason. You can try to reinstall ssh.

1. Login

I am using Tencent Cloud, so I log in on the Tencent Cloud server web page.

You can first find the problem of the server in the work order system

 

 

2. Process

1.service sshd start

 

 2.journalctl -xe

journalctl -xe

An error as shown in the figure appears:

sshd.service: main process exited, code=exited, status=203/EXEC.
init: ssh main process (1843) terminated with status 255.

 

 3. Execute the following command to check the environment variable configuration.

echo $PATH

4. Compare the actual returned PATH environment variable with the default value. PATH environment variable default value:

/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

5. If the actual returned PATH environment variable is different from the default value, you need to execute the following command to reset the PATH environment variable.

export PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

6. Execute the following command to find and confirm the sshd program path.

find / -name sshd

7. If the returned result is as follows, it means that the sshd program file already exists.

/usr/sbin/sshd

8. If the corresponding file does not exist, reinstall the SSH software package.

 8.1 View command:
        rpm -qa openssh*
 8.2 Uninstall command
        yum remove openssh*

8.3 Reinstall the ssh service

        yum -y install openssh-clients

        yum install openssh-server

8.4 After the installation is complete, check whether it is installed:
        rpm -qa|grep ssh

 

8.5 Modify the configuration file

       vim /etc/ssh/ssh_config

        去掉#：Port 22、ListenAddress、PermitRootLogin yes、PubkeyAuthentication yes　

9. Start the ssh service:
systemctl start sshd.service

10. Check the running status of the ssh service:
systemctl status sshd.service

11. Open the 22 port command of the firewall:
sudo firewall-cmd –zone=public –add-port=22/tcp –permanent
sudo service firewalld restart

12. Query the current program running port number:
netstat -anpl |grep sshd

        Port 22 must be monitored

3. Reuse the xshell remote connection successfully