Quick answer: The Forest connection issues: port 27015 UDP, correct serverPassword in server.cfg and started as dedicated.
If you landed here: The Forest shows "Unable to connect", timeout or server not in list.
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Frequently asked questions (FAQ)
Which port for The Forest dedicated server?
27015 UDP (default). Open in server.cfg and firewall/panel.
The Forest "Unable to connect"?
Server still starting (1–2 min), port blocked, wrong password in server.cfg or not started as dedicated.
The Forest dedicated vs peer-to-peer?
Dedicated runs 24/7 on VPS/game server. P2P only when host is online.