Objective: help you identify real problems, avoid bad technical decisions and choose a solution adapted to your server or infrastructure.
Reverse proxy
The reverse proxy is simple for gaming or web uses: traffic arrives on a protected IP, is filtered, then goes back to the real server. This is useful when you want to hide the original IP.
Tunnel GRE
The GRE allows transport of its own traffic to a remote infrastructure. This is interesting for more advanced services, but you have to manage MTU, routing, firewall and tunnel stability.
Announcement BGP
With BGP, the infrastructure advertises its own prefixes via a transit or protection provider. This is the cleanest method for operators, but it requires network skills.
Selection criteria
For an isolated game server, the proxy is often the quickest to deploy. For a complete infrastructure, GRE or BGP become more relevant. The choice also depends on IPs, routing and criticality.
Avoid errors
Do not expose the real IP, monitor the routes, test the MTU, document the firewall rules and keep a rollback plan in case of misconfiguration.
Conclusion
The best approach is to start from the real symptom, check the technical causes, then choose protection adapted to the protocol and the community. An effective solution must protect without degrading the user experience.