Rust Server Missing from the Server List? Check the Query Port

A Rust server can accept player connections through its game port while remaining absent from the in-game server browser if its separate query port is unavailable.

Verify the relevant ports

Setting	Purpose	Protocol
server.port	Player connections	UDP
server.queryport	Server queries and browser listing	UDP
rcon.port	Remote administration	TCP

Facepunch retired game-port and query-port sharing in the February 2, 2023 Industrial Update. The server.port and server.queryport values must be different, and both UDP ports must be open and accessible.

Check the default query port

If server.queryport is not explicitly configured, Rust selects one number higher than the greater of server.port and rcon.port.

For example:

server.port 28015
rcon.port 28016

The resulting query port is 28017. An explicit configuration can make the effective values easier to verify:

server.port 28015
server.queryport 28017
rcon.port 28016

For this example, UDP 28015 and UDP 28017 must be accessible. TCP 28016 is used for RCON. A server behind a router may require port-forwarding rules for the game and query ports.

Check server.cfg for an override

Rust reads the following file at startup:

rust/server/<server.identity>/cfg/server.cfg

Values in server.cfg take priority over command-line values. Settings in this file omit the leading plus or minus sign:

server.port 28015
server.queryport 28017

After editing the file, restart the server so it reads the configuration at startup. Confirm that the effective game and query ports match the UDP firewall and router-forwarding rules.

Test browser discovery separately

A successful player connection through server.port does not show that the query port is accessible. After verifying the configuration, search for the server in Rust and compare Rust servers on Rust You.

If direct connection works but browser discovery does not, verify the effective server.queryport, ensure it differs from server.port, and confirm that it is reachable over UDP.