Securing SSH on your VPS requires implementing multiple layers of protection including disabling root login, using key-based authentication, changing default ports, and enabling comprehensive monitoring. These practices protect against brute force attacks, unauthorised access, and potential data breaches. Proper SSH hardening combines configuration changes, access controls, and ongoing maintenance to create robust server security for your cloud infrastructure.
Why securing SSH on your VPS matters more than you think
SSH security forms the foundation of your VPS protection strategy. When you leave SSH unsecured, you expose your entire server to attackers who constantly scan for vulnerable systems across the internet.
Attackers exploit common SSH vulnerabilities through several methods. They target weak passwords using automated brute force attacks, attempt to gain root access through default configurations, and exploit outdated SSH software with known security flaws. Many attacks succeed because administrators use default settings that prioritise convenience over security.
The consequences of compromised SSH access extend far beyond simple unauthorised entry. Attackers can steal sensitive data, install malware, use your server for cryptocurrency mining, or launch attacks against other systems. Your VPS security becomes the gateway to protecting your applications, databases, and customer information.
What are the most important SSH security settings to change immediately?
Start by disabling root login, changing the default port, and implementing key-based authentication. These three changes eliminate the most common attack vectors that compromise VPS systems.
Disable root login by editing your SSH configuration file and setting "PermitRootLogin no". This prevents attackers from directly accessing your system's most powerful account. Create a regular user account with sudo privileges instead, adding an extra authentication layer.
Change your SSH port from the default 22 to a custom port between 1024-65535. While this doesn't provide complete security, it reduces automated scanning attempts significantly. Update your firewall rules to allow connections on the new port.
Disable password authentication entirely once you've configured key-based access. Set "PasswordAuthentication no" in your SSH configuration to prevent brute force attacks against user passwords. This change makes SSH best practices mandatory for all connections.
| Setting | Default Value | Secure Value | Purpose |
|---|---|---|---|
| PermitRootLogin | yes | no | Prevents direct root access |
| Port | 22 | Custom (1024-65535) | Reduces automated attacks |
| PasswordAuthentication | yes | no | Prevents brute force attacks |
| PermitEmptyPasswords | no | no | Blocks empty password access |
How do you set up SSH key authentication properly?
Generate SSH key pairs using the RSA or Ed25519 algorithms, then configure your server to accept public key authentication whilst maintaining proper key management practices.
Create your key pair on your local machine using "ssh-keygen -t ed25519 -C 'your-email@domain.com'". Ed25519 provides better security than RSA with smaller key sizes. Store your private key securely and never share it with anyone.
Copy your public key to your VPS using "ssh-copy-id username@your-server-ip" or manually append it to the ~/.ssh/authorized_keys file. Set proper permissions with "chmod 700 ~/.ssh" and "chmod 600 ~/.ssh/authorized_keys" to prevent unauthorised access.
Manage multiple keys by creating separate key pairs for different purposes or servers. Use SSH agent forwarding carefully, as it can create security risks in untrusted environments. Implement key rotation by regularly generating new keys and removing old ones from your authorized_keys file.
Which SSH monitoring and logging practices should you implement?
Configure comprehensive SSH logging, monitor failed login attempts, and implement automated blocking systems like fail2ban to detect and prevent suspicious activities.
Enable detailed SSH logging by setting "LogLevel VERBOSE" in your SSH configuration. This captures connection attempts, authentication failures, and user activities. Review your logs regularly using "journalctl -u ssh" or checking /var/log/auth.log depending on your system.
Install and configure fail2ban to automatically block IP addresses after repeated failed login attempts. Create custom filters for SSH-specific attack patterns and set appropriate ban times. Configure email notifications to alert you about persistent attack attempts.
Monitor your SSH logs for patterns indicating potential security threats. Look for repeated failed logins, connections from unusual geographic locations, and attempts to access disabled accounts. Implement intrusion detection systems that can correlate SSH activities with other system events for comprehensive security monitoring.
How do you maintain SSH security with regular updates and audits?
Keep your SSH software updated, conduct regular security audits, and review user access permissions to maintain ongoing protection against emerging threats.
Update your SSH server regularly using your system's package manager. Security patches often address critical vulnerabilities that attackers actively exploit. Enable automatic security updates where possible, but test updates in non-production environments first.
Audit your SSH configuration monthly by reviewing active users, checking authorized_keys files, and verifying that security settings remain properly configured. Remove accounts for users who no longer need access and update keys that may have been compromised.
Document your SSH security policies and ensure team members understand proper key management procedures. Regular security audits help identify configuration drift and ensure your server security measures remain effective against evolving threats.
Your next steps for bulletproof SSH security
Implement these SSH security practices immediately: disable root login, change default ports, enable key-based authentication, configure monitoring, and establish regular maintenance routines.
Create a security checklist covering all configuration changes, monitoring setup, and maintenance schedules. Test your security measures regularly by attempting connections and reviewing logs to ensure everything functions correctly.
We at Falconcloud provide secure cloud infrastructure that supports these SSH best practices through our managed VPS solutions. Our global data centres offer robust network security, automated monitoring, and expert support to help you maintain comprehensive remote access security for your applications and data.