RUST Multithreaded Networking Change

Networking changes are coming, are you ready?

Beginning on February 2nd, 2023, RUST game servers will be required to specify a query port in addition to their current game port to facilitate and support Facepunch’s new multithreaded networking system.

This change is especially important to server owners who utilize the in-game server browser interface to attract new players. Failure to make this change could result in a server not appearing correctly in the in-game server browser.

It’s important to note, despite its precarious timing, this change is not directly linked to changes coming with the upcoming Steam Networking (swnet) swap. More details to follow on this topic as its incorporation for RUST servers becomes mandatory.

What is multithreaded networking?

Multithreading technology allows multiple threads of a single process to be executed concurrently, increasing computing power and significantly improving the overall processing performance. This multithreaded networking change is slated to bring about performance benefits while in-game.

Who is impacted by this change?

This change can impact anyone hosting, developing, or playing on RUST servers.

Server Admins

RUST server owners and admins are burdened with updating their server’s configurations, firewall rules, 3rd party services, documentation, and marketing per the new changes. Be sure to communicate any significant changes made to your community.

Server Hosts

Server hosts must verify that their RUST hosting configurations and firewall rules are correctly set up for their clients and provide updated support documentation and communications.

RUST Players 

RUST players are most likely to experience impacts of this change when browsing in the in-game server, as it is possible for servers that’ve not correctly configured their server to no longer appear.

Depending on how a server’s configurations are updated, players could also see servers disappear from their favorite list inside RUST’s server browser. Additionally, players may experience outdated server connection information across various 3rd party services and websites.

I operate a shared hosting RUST server. What should I do?

Suppose you operate and administer a shared hosting RUST server. In that case, many of these changes may be made on your behalf, so it’s important first to ascertain what is and isn’t being done in preparation for the changes ahead. Don’t assume, or you may be left hanging in the wind.

  • Check with your server host to determine if they are taking action on your behalf.
  • Make sure to update your server’s information in connected 3rd party services such as Battlemetrics, RustAdmin, etc.
  • Update your server’s website, Discord channels, Tebex, and other advertising platforms so that the correct information is displayed to your users and they can connect to your server(s).

I operate a dedicated RUST server. What should I do?

If you operate and administer a dedicated RUST server, you must make a few changes to your server’s startup configuration and firewall rules. Also, consider updating all 3rd party services and information channels with outdated connection information displayed.

This change requires RUST servers to have a separate Steam Query Port set using the queryport server startup parameter. 

If no query port is specified in your start up configuration, the server will automatically default the setting to the (server.port + 1 or rcon.port + 1), depending on which port number is larger. Be sure to open this port on your firewall rules under the UDP protocol.

Note: Setting the query port to 28015 will retain your server in your players’ favorites lists, but this is not required.

The February 2nd update will not be enabling the -networkthread flag, which allows admins to opt-in their server to the new threaded networking. This configuration is and will remain disabled by default for the time being. This update is in preparation for adding both multithreading and SWNet changes in future updates. Facepunch will announce when those changes are ready, but for now, there are no additional steps for you to take

Quick Reference for Port Configurations

Rust+ Appapp.portTCP

Here’s an example Windows Batch script with the changes implemented. If you don’t use Windows, or a Batch script to start your server, you can also apply the port changes to your server.cfg file.

@echo off
C:\steamcmd\steamcmd.exe +force_install_dir C:\rust_server\ +login anonymous +app_update 258550 validate +quit
RustDedicated.exe ^
-batchmode ^
-server.port 28015 ^
-server.queryport 28016 ^
-rcon.port 28017 ^
-app.port 28018 ^
-server.level "Procedural Map" ^
-server.seed 1 ^
-server.worldsize 4250 ^
-server.maxplayers 100 ^
-server.hostname "Server title" ^
-server.description "Server description" ^
-server.url "" ^
-server.headerimage "" ^
-server.logoimage "" ^
-server.identity "MyServerName" ^
-rcon.ip ^
-rcon.password "abc123" ^
-rcon.web 1 ^
-logfile "logfile.txt"
goto start

Final thoughts on the multithreaded networking change

As RUST continues to undergo continuous developmental changes, very rarely do we have such wide-reaching network changes like this, so don’t fret if this caught you off guard.

 If you’re new to hosting RUST servers and you need help with setting up your server, there are numerous admin Discords available, including the official RUST Discord and the CorrosionHour Discord, where you’ll find plenty of helping hands.

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About No Limit Llama

An aspiring woodworker and web designer. Father, husband, and Rust veteran. Llama has written op-eds and official game documents for over two decades. The earliest writings were on Asheron’s Call, followed by World of Warcraft and eventually Rust. The vast majority of his indoor time is spent running Rust servers or helping friends with their Rust-related projects. He enjoys working around the house, continuing his education when time permits, and creating new processes to simplify activities of daily living for his friends and family. He has an incredible wife, a dog, three children, and one granddaughter.

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