Satisfactory Friends Can't Join? Dedicated Server NAT Guide
If your Satisfactory dedicated server cannot be added, shows a Server API failure, hangs while loading, or works on LAN but not for friends, check reachability before changing every server setting.
For current dedicated servers, pay attention to both the game port and the reliable messaging port. On a home server, those ports only help if outside traffic can actually reach your router and the firewall lets it through.
First decide where the failure is
Satisfactory failures should be split by symptom before touching ports. A Server API error, a loading hang, a LAN-only success, and a single player failure are different layers.
- Nobody can connect, even on LAN: read server logs and check server status before router settings.
- LAN works but outside players fail: check NAT, public IPv4, router forwarding, and firewall.
- Server API failure: prioritize the reliable messaging/API path and listening address.
- Only one player fails: check that player local firewall, DNS, account, or network path.
If outside connections fail, check NAT and public reachability
Run the test on the same device and network you use for Satisfactory. The result helps separate ISP/router reachability from game, firewall, and platform problems.
| Result | Meaning for hosting or co-op | Next step |
|---|---|---|
| Full Cone / Open | Usually suitable for inbound connections or direct sessions. | Check firewall, ports, server config, and game version. |
| Restricted / Port Restricted | May work, but success can vary by game and peer. | Try UPnP or manual forwarding, then retest. |
| Symmetric NAT | Often unreliable for peer-to-peer or home-hosted sessions. | Disable VPN/proxy tools, change networks, or use hosting/relay. |
| CGNAT / no public IPv4 | The public internet usually cannot reach your home router. | Ask for public IPv4, or use a VPS, hosted server, or relay. |
If outside players can reach the host, apply the game-specific fix
For Satisfactory, the game-specific fix is concrete: the configured game port and reliable messaging port must both be reachable at the server machine. Router forwarding, cloud firewall, and OS firewall must agree.
Game Port
7777Primary game connection port; verify the configured protocol and forwarding rule.
Reliable Messaging Port
8888Important for newer dedicated server behavior; missing access can cause connection or loading problems.
- Confirm the server config has not changed the default ports.
- Forward to the server device static LAN IP.
- Allow the ports or server process in Windows/Linux firewall.
- Check multihome, virtual adapters, Docker networking, and listen address issues.
If direct joining works but the symptom remains, check the next layer
If players can connect directly but the server is awkward to add, appears inconsistently, or hangs during management/API checks, stop treating it as a generic router issue and check the server layer.
- Server API failure: prioritize 8888, firewall, and listening address.
- Server appears but loading hangs: confirm versions, server status, and both configured ports.
- Check multihome, virtual adapters, Docker networking, and listen address issues.
- Confirm the server config has not changed the default ports.
When router changes will not fix it
If the ISP does not give you a public IPv4 address, your router is only a client behind the ISP private network. Forwarding 7777 or 8888 on your home router controls only your local NAT layer. Outside players still cannot reach your router through the ISP NAT layer.
- Ask the ISP for a public IPv4 address.
- Use a VPS or hosted server.
- Use a tunnel or relay only if you accept the latency and reliability tradeoff.
- Let a friend with better network conditions host.