Astroneer dedicated server setup and ports

An Astroneer dedicated server is a free Windows program (Steam app 728470, anonymous download) that runs one save for up to eight players. It is configured through two files in Astro/Saved/Config/WindowsServer/: Engine.ini, which holds the game port (8777 UDP by default), and AstroServerSettings.ini, which holds everything else - name, password, owner, public IP, save intervals and the player list. The single setting that breaks most first attempts is PublicIP: the server registers itself with the game's backend using that address, and if it is wrong the server either does not appear or cannot be joined. Set it to the address players will actually connect to, open UDP 8777, and the rest is detail.

How Astroneer dedicated servers work#

Astroneer multiplayer comes in two forms. A hosted game runs on one player's PC and exists only while they play. A dedicated server runs the save on its own, so anyone in the group can play at any time and long-running automation keeps going.

A few things are specific to Astroneer:

• Eight players maximum. MaximumPlayerCount cannot usefully go beyond 8.
• Windows only. The server is AstroServer.exe. It runs on Linux under Wine, which many people do successfully, but it is not supported and updates occasionally break it.
• Server registry. The server does not use a classic Steam master server list. It registers with the game's online backend, and players add it to their server list by address. That is why PublicIP matters so much.
• PC only. Dedicated servers are for Steam and Microsoft Store players on PC. Console players use hosted sessions instead.

There is also a well-known community tool, AstroLauncher, that wraps the server on Windows. It manages the config files, handles restarts and backups, checks the network setup, and adds a small web interface. It is not official, but it fixes enough of the server's rough edges that most self-hosted Astroneer servers on Windows use it. On a game panel the panel plays the same role, so you do not need it there.

Dedicated server or hosted session?

For two friends who always play together, a hosted session is fine: whoever hosts starts the game, the other joins, and the save lives on the host's PC. The trouble starts when the group grows or schedules drift apart. The save is only reachable when the host is online, the host's frame rate is shared with the simulation, and when the host leaves, everyone else is dropped. Moving the save to another player means copying files around by hand.

A dedicated server fixes each of those. The save sits on a machine that is always on, anyone in the group can log in at any hour and pick up the project, and nobody's PC carries the world. It also changes what kind of game Astroneer becomes: automation that only runs while somebody is present - smelters, research chambers, trade platforms - can be left running while one player tends it, so progress no longer waits for the whole group.

What it does not change is the game's limits. Eight players is still the cap, the same save format is used, and the server is no better at large automated bases than a powerful gaming PC would be. If your hosted game already stutters at a huge base, a dedicated server with similar clock speed will stutter too. The gain is availability and fairness between players, not raw performance.

Running it under Wine on Linux

Because the server is a Windows executable, Linux hosting means running it through Wine. That is how many panel-based hosts and community container images run it, and for a private group it is usually fine. The costs are worth knowing before you commit:

• Updates can break the setup. A game update that changes something Wine handles badly can leave the server failing at start until the Wine version or container image is updated.
• Troubleshooting is harder. Error messages pass through an extra layer, and official support assumes Windows.
• Performance is close to native for a server of this size, so that is rarely the reason to avoid it.

If you need the most predictable setup, a Windows machine you control - a VDS, for example - is the safe route; choosing between a VDS and a game panel weighs the extra administration against the control you gain.

Requirements and resource usage#

Astroneer's server is light at first and grows with the save. Big automated bases with long conveyor-like chains of storage, many rovers, and large terraformed areas push memory and CPU up over weeks.

• CPU: the simulation and physics lean on one main thread, so clock speed matters. MaxServerFramerate caps how hard it runs (see below).
• Disk: the server installs to a few gigabytes. Saves start at a few megabytes and grow into tens of megabytes; with automatic backups kept, give it 10 GB.
• Network: modest bandwidth, but latency shows up as rubber-banding rovers and delayed item pickups. Latency, jitter and packet loss covers how to tell them apart.

Installing and first start#

With SteamCMD on Windows:

$ steamcmd +force_install_dir C:\astro-server +login anonymous +app_update 728470 validate +quit

SteamCMD explained covers the update loop and validate. Run AstroServer.exe once and let it start fully, then stop it. That first run creates the Astro\Saved\Config\WindowsServer folder with Engine.ini and AstroServerSettings.ini, and a SaveGames folder.

The sequence that works:

1. Start the server once to generate the config files.
2. Stop it.
3. Set the port in Engine.ini and the settings in AstroServerSettings.ini, including PublicIP and OwnerName.
4. Open UDP 8777 (or your chosen port) on every firewall between the server and the internet.
5. Start the server and have the owner join first.

Engine.ini: the port#

The game port lives in Engine.ini, not in the server settings:

[URL]Port=8777

Change it only if your host has given you a different port, or you run several servers on one machine. The port is UDP. If you change it, every player has to use the new number when adding the server.

Older guides also tell you to add a [SystemSettings] block with net.AllowEncryption=False to Engine.ini - and, in some versions, to the players' own Engine.ini too - to fix connection failures. That was a real workaround for some builds; on current builds it is usually unnecessary, but it remains one of the first things the community suggests when a correctly configured server still refuses connections.

AstroServerSettings.ini, key by key#

The file holds a single section. A typical edited version:

[/Script/Astro.AstroServerSettings]bLoadAutoSave=TrueMaxServerFramerate=30.000000MaxServerIdleFramerate=3.000000bWaitForPlayersBeforeShutdown=FalsePublicIP=203.0.113.10ServerName=Exo Dynamics AnnexMaximumPlayerCount=8OwnerName=NovaPilotOwnerGuid=PlayerActivityTimeout=0ServerPassword=a-long-join-passwordbDisableServerTravel=FalseDenyUnlistedPlayers=FalseVerbosePlayerProperties=TrueAutoSaveGameInterval=900BackupSaveGamesInterval=7200ActiveSaveFileDescriptiveName=SAVE_1ConsolePort=1234

What each setting does:

PublicIP

Set it to the address players use to reach the server - on a rented server, the address shown in the panel. On a home server behind a router it is your public internet address, not the 192.168.x.x address of the PC. If it changes (home connections often do), the server registers the wrong address and players cannot join until you update it. Hosted servers do not have that problem, which is one of the honest arguments covered in self-hosting a game server at home vs renting.

Owner, admins and the whitelist

OwnerName is the Steam display name of the person who should own the server. The first time a player with that name joins, the server records their ID in OwnerGuid, and from then on that account is the owner whatever its name becomes.

The owner manages everyone else from inside the game, in the server's player list: promoting players to admin, whitelisting, kicking and blacklisting. The server writes these into the settings file as player entries with a category - Owner, Admin, Whitelisted, Blacklisted or Unlisted. DenyUnlistedPlayers=True then turns the server into a whitelist: only players already in the list can join. The usual flow for a private group is to leave it False, have everyone join once so they appear in the list, whitelist them, and then switch it to True.

Framerate settings

MaxServerFramerate caps how often the server simulates per second while players are online. The default 30 is fine for most saves. Raising it can smooth physics-heavy play but costs CPU in proportion, and the gain is small. MaxServerIdleFramerate is the rate when nobody is online; keeping it low means an empty server barely uses CPU. If you want automation to keep running at full speed overnight, raise the idle rate, but be aware the save keeps changing with nobody watching it.

Ports and connecting#

Astroneer needs only the one game port open to the internet. The console port is for tools on the same machine or network - there is no reason to forward it, and an exposed management port is an invitation. Game server ports explained covers the general difference between game and management ports.

To join, a player opens the server list in the game, adds a server with the address and port (203.0.113.10:8777), and it appears in their list with its name and status. The password is asked for on join. If the server is listed as unreachable for everyone, the problem is almost always PublicIP or the firewall.

Moving a local save onto the server#

Single-player and hosted saves can be moved to a dedicated server. Local saves on a Steam install live in:

%LOCALAPPDATA%\Astro\Saved\SaveGames\

The steps:

1. Stop the server.
2. Copy the .savegame file you want into the server's Astro\Saved\SaveGames folder - SFTP and the file manager covers getting files onto a hosted server.
3. Save file names carry a descriptive name followed by a $ and a date stamp. Set ActiveSaveFileDescriptiveName to the part before the $.
4. Start the server and check the log to confirm it loaded that save rather than creating a new one.

If the server creates a fresh save instead, the descriptive name did not match. Look at the exact file name, including capitals, and try again. The original file is still there - nothing is lost.

Saves, backups and updates#

Astroneer autosaves every AutoSaveGameInterval seconds (15 minutes by default) and makes a backup copy every BackupSaveGamesInterval seconds (two hours by default), keeping them in the same SaveGames folder. A clean stop saves first; a killed process loses everything since the last autosave.

Those built-in backups protect against a save corrupting, not against losing the server or deleting the wrong folder. Copy saves off the machine on a schedule, and occasionally restore one to check it works - backups that actually restore explains why that check is the point.

Updates: after a game patch, the server must be updated before patched clients can join. Update through SteamCMD, start the server, and check it loads the existing save. Take a backup before every update; large updates have been known to change save handling.

Lowering AutoSaveGameInterval to 300 seconds limits what a crash costs on a busy save. The save hitch is brief on small saves and only becomes noticeable late in the game.

On RE:NODE, backup slots are included on every game plan, stored off the machine they protect and restored with a button, and the Schedules tab can run a backup before a restart. Astroneer's server is Windows-only and not in the catalogue, so this describes the panel, not an Astroneer plan.

Troubleshooting#

The server does not show as online in the list. PublicIP is wrong or empty, or UDP 8777 is closed. Check both before anything else.

Players get stuck on "Connecting" and time out. Usually the port is open for TCP instead of UDP, or the port in Engine.ini does not match what you opened. The encryption workaround above is the next thing to try.

The owner has no rights. OwnerName did not match their Steam display name when they first joined, so someone else may have been recorded, or nobody. Stop the server, clear the wrong OwnerGuid, set the name exactly, and have them join first.

The server loads a new world instead of the uploaded save. ActiveSaveFileDescriptiveName does not match the file name before the $.

Settings revert after a restart. You edited while the server was running. Stop, edit, start.

Rovers and items rubber-band. CPU at its limit or latency. Check the CPU graph under load; on a late-game save, reducing automation or splitting bases helps more than anything in the config. See CPU vs RAM for game servers.

FAQ#

How many players can an Astroneer dedicated server hold?

Eight. The game is designed around that number, and the server setting does not usefully go higher.

Can Xbox or PlayStation players join a dedicated server?

No. Dedicated servers are for PC players on Steam and the Microsoft Store. Console players use hosted sessions.

Does the Astroneer server run on Linux?

Only under Wine. It works for many people, but it is not supported, and updates have broken Wine setups before. Windows is the dependable choice.

What is the difference between autosave and backup intervals?

Autosave writes the current save; the backup interval copies it to a separate backup file. Both stay in the same folder, so neither replaces backups kept somewhere else.

Do I need AstroLauncher?

Not on a game panel, which already handles start, stop, restarts and backups. On a self-managed Windows server it is useful, because it automates exactly those chores and checks your network settings.