Connecting to Your CentOS VPS Remotely with SSH

#### Prerequisites Before you begin, ensure you have: - A CentOS VPS (This guide is tested with CentOS 8) - A user account with sudo privileges - Basic familiarity with the command line - An SSH client (like OpenSSH on Linux/macOS or PuTTY on Windows) #### Step 1: Find Your Server’s IP Address To connect to your VPS, you need to know its public IP address. This information is typically provided by your hosting provider. #### Step 2: Open Your SSH Client Depending on your operating system, open your SSH client: - **Linux/macOS:** Open a terminal window. - **Windows:** Open PuTTY or a similar SSH client. #### Step 3: Connect to Your Server Use the SSH command to connect to your server. The basic syntax is: ```bash ssh your_username@your_server_ip ``` Replace `your_username` with your actual username and `your_server_ip` with your server's IP address. Example: ```bash ssh john@192.0.2.1 ``` If this is your first time connecting to the server, you will be prompted to verify the server's authenticity. Type `yes` and press Enter to continue. #### Step 4: Enter Your Password When prompted, enter the password for your user account. Note that the password will not be visible as you type for security reasons. ```plaintext john@192.0.2.1's password: ``` #### Step 5: Basic SSH Commands Once connected, you can run commands on your VPS. Here are a few basic commands to get you started: - **Update system packages:** ```bash sudo dnf update -y ``` - **Create a new directory:** ```bash mkdir new_directory ``` - **List files in a directory:** ```bash ls -la ``` #### Step 6: Secure Your SSH Connection To enhance the security of your SSH connection, consider the following practices: - **Disable root login:** Open the SSH configuration file: ```bash sudo nano /etc/ssh/sshd_config ``` Find the line `PermitRootLogin` and set it to `no`: ```plaintext PermitRootLogin no ``` Save and exit the file, then restart SSH: ```bash sudo systemctl restart sshd ``` - **Change the default SSH port:** In the same SSH configuration file, find the line `#Port 22` and change it to a different port number, e.g., `Port 2222`. ```plaintext Port 2222 ``` Save and exit the file, then restart SSH: ```bash sudo systemctl restart sshd ``` Ensure the new port is allowed in your firewall settings: ```bash sudo firewall-cmd --permanent --add-port=2222/tcp sudo firewall-cmd --reload ``` - **Use SSH key authentication:** Generate an SSH key pair on your local machine: ```bash ssh-keygen -t rsa -b 2048 ``` Copy the public key to your VPS: ```bash ssh-copy-id -i ~/.ssh/id_rsa.pub your_username@your_server_ip ``` Edit the SSH configuration file on your VPS to ensure `PasswordAuthentication` is set to `no`: ```bash sudo nano /etc/ssh/sshd_config ``` Find the line `PasswordAuthentication` and set it to `no`: ```plaintext PasswordAuthentication no ``` Save and exit the file, then restart SSH: ```bash sudo systemctl restart sshd ``` #### Step 7: Disconnect from Your Server When you are done, type `exit` to disconnect from your VPS: ```bash exit ``` #### Conclusion You have learned how to connect to your CentOS VPS remotely using SSH and implement basic security measures to protect your connection. Regularly review and update your SSH settings to ensure ongoing security. **Additional Resources:** - **SSH Documentation:** [https://www.openssh.com/manual.html](https://www.openssh.com/manual.html) - **CentOS Documentation:** [https://www.centos.org/docs/](https://www.centos.org/docs/)