A password
Set the Server Password on the Passwords card. The Admin Password on the same card is for admin commands and RCON; keep it different.
A whitelist
- Open the Player Role Settings card.
- Under Exclusive Players, choose Add to pick a player who has played on the server, or Add by ID to enter a Steam ID.
- Turn on the switch below the heading, so it reads Exclusive mode enabled. Only listed players can join.
- Restart the server.
Questions
Can a whitelist cover all maps of a cluster?
Yes. Add the other maps on the Player Role Settings card's Sharing tab, and every map uses one list.
Which ID goes in the whitelist?
The player's Steam ID, the long number ARK uses for players on PC. ListPlayers in the RCON console shows the IDs of everyone online, and Add picks players who have joined without one.