Basic Firewall Checklist for VPS Beginners

A firewall is one of the basic security controls for a VPS.

Its purpose is to control network traffic and reduce unnecessary exposure.

For beginners, firewall configuration can appear complicated.

The basic principle is simple:

Only allow the network traffic that your server actually needs.

Why Does a VPS Need a Firewall?

A VPS is directly connected to the internet.

Attackers can scan public IP addresses and look for accessible services.

A firewall can reduce exposure by restricting unnecessary network connections.

Identify Required Services

Before configuring a firewall, list the services running on the server.

For a web server, common requirements may include:

• SSH
• HTTP
• HTTPS

If the server hosts email, additional ports may be required.

If a control panel is installed, its required ports must also be considered.

Do Not Open Every Port

A common beginner mistake is allowing all incoming traffic.

This defeats much of the purpose of a firewall.

Only allow ports required by legitimate services.

Protect SSH

SSH is one of the most important administrative services on a Linux VPS.

Review:

• Who can log in
• Which authentication method is used
• Whether root login is necessary
• Whether password authentication should be restricted
• How repeated login attempts are handled

Use strong authentication.

Use SSH Keys Where Appropriate

SSH keys can provide strong authentication.

Store private keys securely.

Never share a private key publicly.

Restrict Administrative Access

If practical, limit administrative services to trusted networks or users.

This can reduce exposure.

However, do not create rules that accidentally lock yourself out of the server.

Allow Web Traffic

If the VPS hosts a website, HTTP and HTTPS traffic usually needs to be allowed.

HTTPS should be preferred for production websites.

Check IPv4 and IPv6

If your VPS uses IPv6, make sure firewall rules are configured for it as well.

Securing IPv4 while leaving IPv6 unrestricted can create an unexpected exposure.

Review Firewall Rules

Firewall rules should be documented.

Know:

• What port is open?
• Why is it open?
• Which service uses it?
• Who needs access?

Remove rules that are no longer required.

Monitor Failed Connections

Logs can show repeated attempts to access services.

A large number of failed login attempts may indicate automated scanning or brute-force activity.

Do not assume every failed login is an attack, but investigate unusual patterns.

Firewall Is Not Enough

A firewall does not make a VPS completely secure.

You still need:

• Software updates
• Strong authentication
• Secure applications
• Backups
• Monitoring
• Access control

Protect Web Applications

If WordPress is running on the VPS, WordPress security is still required.

A firewall cannot fix an outdated plugin or compromised administrator password.

Avoid Random Firewall Commands

Do not copy firewall commands from an unknown source without understanding them.

A single incorrect rule can block SSH or web traffic.

Always maintain a recovery method before changing firewall configuration.

Test After Changes

After applying firewall changes:

1. Test SSH.
2. Test the website.
3. Test HTTPS.
4. Test required applications.
5. Review logs.

Do not close your current administrative session until you confirm that new connections work.

Final Thoughts

A firewall should reduce unnecessary network exposure without preventing legitimate services from working.

Start with a list of required services, allow only necessary traffic, secure SSH, review rules, and maintain a recovery plan.

THE HOSTGURU Linux VPS users should treat firewall configuration as part of regular server security rather than a one-time task.

Frequently Asked Questions