4. Troubleshooting

This section addresses the troubleshooting process for your Day of Defeat server. It covers everything from setting up the game's legacy version to implementing critical server enhancements.

Whether you're encountering setup difficulties or issues with server upgrades, this is your go-to resource for troubleshooting and resolutions.

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4.1 Address Connection Issues

When attempting to join your Day of Defeat server and encountering the persistent status Establishing a network connection..., despite the server seeming operational as indicated by ./dodserver details, the issue may often lie within the server's firewall configurations, potentially blocking the necessary ports for game communication.

Establish a Secure Connection

To securely connect to your VPS, utilize SSH by substituting <ip-address> with your server's actual IP address:

ssh root@<ip-address> -p 22

Configure Firewall for Enhanced Security

Properly configuring your VPS firewall is essential to protect your server while ensuring it remains accessible for the required game traffic. This section provides a step-by-step guide to securing your server with Uncomplicated Firewall (UFW), balancing security and functionality.

Enable UFW

You can begin by enabling UFW to start adding rules. If `it is not installed, you can typically install it with:

apt update && apt install ufw -y

Then, enable UFW with:

ufw enable

Block Non-Required Ports

Initially, set UFW to deny incoming connections and allow all outgoing connections by default, enhancing privacy and security:

ufw default deny incoming && ufw default allow outgoing

Allow Game-Specific Ports

Day of Defeat, along with many multiplayer games, primarily uses specific ports for communication. To facilitate necessary traffic, open the ports ranging from 27005 to 27015:

ufw allow 27005:27015/tcp && ufw allow 27005:27015/udp

These commands will ensure both TCP and UDP traffic for your game server can flow without hindrance, which is vital for game server functionality.

Secure SSH Access

To manage your server via SSH and prevent being locked out, explicitly allow SSH connections:

ufw allow ssh

Persist Firewall Settings

UFW settings and rules automatically apply at startup, ensuring your firewall configurations persist across reboots without additional steps.

Additional Security with fail2ban

To further enhance security by automatically blocking IP addresses following repeated failed login attempts, thereby protecting against brute-force attacks, consider installing fail2ban:

apt install fail2ban -y

fail2ban is pre-configured for essential protection and typically requires no additional setup.

Following these guidelines enhances your server's defence against unauthorized access while optimizing it for Day of Defeat gameplay, ensuring a secure and enjoyable gaming environment for players.