Relay Server Hardening: Best Security Practices for 2026

Default settings are for testing. Professional deployments require hardening. In 2026, the stakes are too high to leave your relay wide open. Here is your security checklist.

1. Disable the Public ID server

If you are using RustDesk Pro, you should never be using the public relays. Ensure your clients are locked to your specific ID and Relay server IP.

2. Mandatory Public Key Encryption

Never run a server without the -k _ parameter. This ensures that only clients who possess your public key can even attempt to talk to your relay. It prevents “parasitic” use of your bandwidth.

3. SSH Key-Only access

If you still have password authentication enabled on your Linux host, you have a massive hole. Disable passwords and use Ed25519 SSH keys for any administrative access.

4. Fail2Ban for Port 21116

Even with encryption, bots will try to probe your ports. Failed connection attempts should result in an immediate IP ban at the firewall level.

5. Regular Key Rotation

Just like passwords, your server keys should be rotated annually. RustDesk Pro makes this easier to manage across your fleet.

Hardening is not a one-time event; it’s a culture of IT security. At DeployRD, these hardening steps are baked into our automated deployment process by default.