If you’ve been hit by a DDoS and want to understand what actually happened and what actually stops it, here’s a breakdown based on dealing with this on my own servers.
Why your server goes offline
FiveM uses UDP for all game traffic. UDP has one fundamental weakness: anyone can send a UDP packet to any IP, and your server has to process it before it can decide to drop it. Attackers flood you with millions of junk packets until your bandwidth saturates or your connection gets null-routed by your host.
Amplification makes this worse — attackers spoof your IP and send small requests to misconfigured DNS/NTP servers worldwide, which reply with large responses directed at you. A 100 Mbps attack becomes 1 Gbps.
What doesn’t work
Cloudflare — proxies HTTP/HTTPS only. FiveM game traffic is UDP. Cloudflare protects your website, not your game port.
Your VPS firewall — iptables/nftables work at the kernel level, after packets enter your server’s networking stack. During a large flood, the overhead of processing millions of packets per second through the kernel causes degradation before any bandwidth limit is even reached. And if your host detects DDoS traffic at their edge, they null-route your IP anyway.
Hiding your port — your IP is publicly listed in the FiveM server browser. Obscurity doesn’t help.
What actually works
A dedicated UDP reverse proxy in front of your server with filtering built specifically for FiveM traffic:
Attacker ─────────────────────────── X (dropped at proxy)
Player ──► proxy-ip:30120 ──► [XDP filter] ──► your-real-server:30120
Your real server IP is never exposed. The proxy sits at a network edge with hundreds of Gbps of upstream capacity. Key requirements:
- XDP filtering — processes packets at the network driver level, before the kernel stack. Handles millions of packets/second with near-zero CPU. iptables collapses under this load; XDP doesn’t.
- Player whitelisting — only forwards packets from IPs that completed a valid FiveM connection handshake, drops everything else
- IP lockdown on your origin — your server only accepts connections from the proxy’s IP range
The false positive problem nobody talks about
Here’s what most anti-DDoS marketing doesn’t mention: generic scrubbing centers (OVH VAC, Path.net, Akamai Prolexic) regularly kick legitimate players, and for FiveM this is a serious issue.
These services are built for web and enterprise traffic. FiveM’s UDP profile is unusual by design — players send bursts of small packets, connection patterns vary heavily by game mode, and FiveM’s handshake looks nothing like standard protocols. Generic detection models flag this regularly:
- CGNAT / shared IPs (university networks, mobile carriers, corporate VPNs) — one bad actor on the same IP gets the entire range blocked, taking out all your players behind that carrier
- High packet-loss connections (mobile data, satellite) — aggressive retries pattern-match to flood behavior, auto-block
- Burst gameplay — explosions, vehicle spawns, mass player joins during peak hours spike UDP rates into ranges the scrubber considers suspicious
- Geographic rate limits — entire IP ranges from regions flagged as “high risk” get throttled, blocking those players entirely
You stop the DDoS but find 10–20% of your legitimate players can no longer connect, with zero visibility into which players or why.
A FiveM-specific proxy avoids this by applying context-aware filtering instead of generic thresholds:
- Whitelist a player after they complete FiveM’s handshake — then forward their traffic without volume checks regardless of burst behavior
- Apply rate limits per session, not per IP — players on CGNAT each have their own session token evaluated independently
- Drop packets that don’t match FiveM’s known byte-level signatures rather than blocking IPs by volume
DIY route
- Rent a dedicated server at OVH (infrastructure anti-DDoS included)
- Set up UDP forwarding with nftables
- Write or adapt an XDP program for FiveM’s UDP traffic pattern
- Lock your origin server to only accept traffic from that proxy’s IP
This works but takes several days and solid Linux networking knowledge. OVH’s built-in protection is good but generic — it will have the false positive issues described above since it isn’t tuned for FiveM.
What I built
After getting hit repeatedly on my own servers I built fiveshield — a managed reverse proxy for FiveM/RedM with XDP filtering, per-session whitelisting, and 9+ proxy locations globally.
Full technical breakdown including the false positive problem in more depth: FIVESHIELD | How to Stop DDoS Attacks on Your FiveM Server (Complete Guide)
Happy to answer questions about the DIY route too.