Satisfactory server: friends stuck or can't join?

Quick answer

Since Patch 1.1 a Satisfactory dedicated server needs two ports: 7777 over both TCP and UDP (game traffic plus the HTTPS API) and TCP 8888 (reliable messaging). If 8888 isn't forwarded, players start connecting and then sit on the loading screen. The other common problems: friends used Join Game instead of the Server Manager ("Encryption token missing"), the router forward maps a different external port to 7777 (not supported), the server isn't claimed yet, or your ISP uses CGNAT. Ports 15000 and 15777 from older guides are no longer used.

Ports

• 7777 UDP: Game traffic and Lightweight Query API (-Port=)
• 7777 TCP: Server traffic and HTTPS API (-Port=)
• 8888 TCP: Reliable messaging (-ReliablePort=). Required since 1.1

How to fix it, step by step

1. Install and start the server. SteamCMD: app_update 1690800 validate with anonymous login (or the free Epic add-on / Steam Tools). Start FactoryServer.exe -log -unattended on Windows or ./FactoryServer.sh on Linux.
2. Claim it in the Server Manager. In the game, open Server Manager, add the server by IP and port, then set a server name and admin password. A server must be claimed before it can start a game.
3. Forward 7777 TCP+UDP and TCP 8888. Reserve the server PC's local IP and forward 7777 (TCP and UDP) and TCP 8888 to it. External and internal 7777 must be the same number: port redirection isn't supported for the standard port. Only the reliable port can be remapped (-ExternalReliablePort=).
4. Open the firewall. Windows PowerShell: allow inbound UDP 7777, TCP 7777 and TCP 8888 (New-NetFirewallRule ... -LocalPort 7777 etc.). Linux with UFW: ports=7777/udp|7777/tcp|8888/tcp.
5. Check it's listening. From another PC on your network, open https://server-lan-ip:7777 (accept the certificate warning) or run curl -k https://IP:7777. A route_handler_not_found error means the server is up. If 7777 was busy, the server quietly moved to the next port, so check which port it really uses.
6. Friends join from the Server Manager. Give friends your public IP (and port if it isn't 7777). They add it in Server Manager and join there, not with Join Game. The game sends the reliable port to them automatically.
7. Test from outside and check CGNAT. If LAN works but outside doesn't, test from a phone hotspot and compare your router's WAN IP with your public IP (see the CGNAT guide).

Errors and what they mean

• Stuck on the loading screen: TCP 8888 (reliable port) isn't forwarded.
• Encryption token missing: the player used Join Game. Add the server in Server Manager and join from there.
• Certificate Verify Result: certificate is not yet valid: a PC clock is wrong. Fix the time; if it was the server's, stop it and delete ServerSettings.PORT.sav.
• Failed to connect to the Server API over IPv6: put brackets around the IPv6 address.
• Two EOS warnings after start (NAT Detection Failed, analytics disabled): harmless.

Consoles and versions

Dedicated servers aren't available for the console release. Steam and Epic players can both join. If you play on Experimental, install the server's experimental branch (-beta experimental); -beta public switches it back to stable.

Test it from the outside

Your own Wi-Fi can't tell you whether friends can reach the server. The free Server Doctor check contacts your server once from the internet, the way the game does, and tells you the most likely cause. The same check runs in Discord with /fix.

No PC to host 24/7?

A Satisfactory server wants 8 GB of RAM or more and a fast CPU, and the factory only runs while it's on. Behind CGNAT, home hosting can't work. A hosted Satisfactory server keeps the factory online with its own public IP.

Related guides

• Friends can't join your Factorio server?
• Enshrouded server not showing up, or friends can't join?
• Valheim server not showing up, or friends can't join?
• Behind CGNAT? Host a game server without port forwarding.
• All guides

Sources: satisfactory.wiki.gg/wiki/Dedicated_servers