Linux SSH Service Configuration: Remote Connection and Security Settings
SSH is a secure protocol for remotely managing Linux servers, replacing the plaintext-transmitted Telnet. Installation requires installing openssh-server on the server using apt (for Ubuntu/Debian) or yum/dnf (for CentOS), followed by starting the service and enabling it to launch on boot. For connection, Windows users can use PuTTY or the system's built-in client, while Linux/macOS users can directly execute the ssh command in the terminal. The core configuration is in sshd_config, where it is recommended to change the port (e.g., to 2222), disable direct root login, and switch from password authentication to key-based login (by generating a key pair locally and copying the public key to the server). The corresponding port must be opened in the firewall. Key-based login enhances security, and changes take effect after restarting the service. Common issues can be checked via logs, and permission errors may require setting ~/.ssh permissions to 700 and authorized_keys to 600. These key security settings ensure secure remote management.
Read MoreSSH Service Configuration: A Detailed Explanation of Linux Remote Connection
SSH is a secure remote login protocol that encrypts data transmission, used for remote management of Linux servers (such as cloud servers and local servers), replacing insecure protocols like Telnet. Key configuration steps: Install `sshd` on the server (using `apt` for Debian/Ubuntu, `yum` for CentOS/RHEL), start it and set it to boot automatically (`systemctl start/ enable sshd`). Modify `/etc/ssh/sshd_config` (backup first). Critical configurations: Change the port (e.g., 22→2222 to prevent brute-force attacks), disable root login (`PermitRootLogin no`), allow specific users (`AllowUsers`), and disable password login in favor of key-based authentication (generate a key pair locally and use `ssh-copy-id` to transfer it to the server). Restart `sshd` after changes. Client connection: Use PuTTY on Windows, and the terminal on Linux/macOS with the command `ssh username@IP -p port`; key-based authentication is more secure. Security notes: Allow the port through the firewall (UFW or cloud security groups), disable direct root login, and regularly update the system and SSH. Common issues: Timeout (check IP/network), connection refused (check port/service), permission errors (
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