Cómo Configurar un Servidor SSH en CentOS 7 2019 Minimal

Configuring SSH Server on Minimal Linux

Introduction to SSH Configuration

• The video introduces the process of configuring an SSH server on a minimal installation of Linux (version 107.6) without a graphical interface.

• A manual for this configuration is available on infobae.com, providing additional guidance.

Checking Installed Packages

• To verify if the necessary packages for SSH are installed, the command rpm -q | grep ssh is used.

• The relevant package files can be found in /etc/ssh, specifically looking for sshd_config.

Editing the SSH Configuration File

• The default port (22) is changed to 2244 as per the manual instructions.

• The line for IPv6 is retained while specifying the server's IP address (192.168.20.2).

• Protocol version 2 is enforced by adding a new line in the configuration file.

Authentication Settings

• Modifications are made to authentication settings: root access is disabled and limited to three login attempts.

• After saving changes, the SSH service is started using systemctl start sshd.

Firewall Considerations

• The firewall may need adjustments; ports 22 and 2244 should be opened if enabled.

• For testing purposes, it’s suggested to stop the firewall temporarily.

Connecting from Windows Client

• Using PuTTY, users connect to the server with IP address 192.168.20.2 and port 2244.

• If connection issues arise, troubleshooting steps include checking connectivity with ping commands.

Successful Connection and Privilege Escalation

• Upon successful connection, users log in with their credentials and can execute commands remotely.

• Users can escalate privileges by switching to superuser mode after entering correct passwords.

Enabling Additional Services

• Various services such as DHCP, FTP, HTTP are enabled to start automatically upon system boot.

Final Testing Steps

• Ensure that both client and server are on the same network segment before attempting connections again.