To make an Icarus dedicated server, install RocketWerkz’s separate Steam application (App ID 2089300) with SteamCMD, forward the game and query UDP ports, launch IcarusServer.exe with logging enabled, let the first lobby or prospect generate the save structure, and then edit ServerSettings.ini. The official setup uses Windows and does not require an Icarus license for the anonymous SteamCMD install. Once the server is running, players join through Icarus’s dedicated-server browser using the server name, address, ports and password.
What do I need before setting up an Icarus dedicated server?
You need a Windows computer or Windows server that can stay online, a SteamCMD download, administrator access to the machine and router, and a stable network connection. The canonical RocketWerkz instructions are Windows-oriented; Linux or Wine setups are community workarounds rather than a supported path in that guide.
- A host machine: use a PC or rented Windows instance that can run the dedicated-server executable continuously. The published setup material does not specify authoritative CPU, memory, storage or bandwidth minimums, so choose capacity according to your player count and test your own workload.
- Router and firewall access: you must be able to create UDP port-forwarding rules and allow the same ports through Windows Firewall or another host firewall.
- SteamCMD: Valve’s command-line Steam distribution tool installs and updates the server files.
- Backups: keep a separate copy of configuration and prospect saves before changing settings or migrating a world.
Installing through SteamCMD is separate from installing the game client. RocketWerkz states that an anonymous SteamCMD installation of the dedicated server does not require an Icarus license.
How do I install the Icarus server with SteamCMD?
Download and extract SteamCMD, open its command prompt, choose a dedicated installation directory, sign in anonymously and install App ID 2089300. The following commands are the complete initial install sequence.
- Open SteamCMD and set the destination folder. This example uses
C:IcarusServer:force_install_dir C:IcarusServer - Log in without a personal Steam account:
login anonymous - Install and validate the dedicated-server files:
app_update 2089300 validate - Wait for SteamCMD to report completion, then close it or leave it ready for later maintenance.
Run app_update 2089300 validate again whenever you want to update the server. Validation checks the installed files and replaces missing or damaged data. Stop the running server before updating so files are not locked while SteamCMD works.
Which ports does an Icarus server use?
The documented defaults are UDP 17777 for game traffic and UDP 27015 for the Steam query and server-list function. Both ports must be forwarded by your router to the host computer and allowed through its firewall.
| Function | Default protocol and port | Where to configure it |
|---|---|---|
| Game connections | UDP 17777 | Router port-forward and host firewall; launch parameter -PORT=17777 |
| Steam query/server list | UDP 27015 | Router port-forward and host firewall; launch parameter -QueryPort=27015 |
You can choose different values with -PORT= and -QueryPort=. If you do, change every matching router and firewall rule; forwarding the defaults while launching on custom ports leaves the server unreachable or invisible in the browser. Use UDP rules, not TCP-only rules.
How do I create the Windows port-forwarding rules?
- Give the host computer a stable local address, either with a DHCP reservation in the router or a static address configured for your network.
- In the router’s port-forwarding page, forward UDP 17777 to that address.
- Create a second rule forwarding UDP 27015 to the same address.
- In Windows Firewall with Advanced Security, allow inbound UDP traffic on both ports, or allow the server executable when prompted.
- Record the public address friends will use. If your internet service changes that address, players will need the new one unless you use a separately configured dynamic-DNS service.
Do not expose unrelated management ports. Only the game and query ports are required by the documented launch setup.
How do I launch IcarusServer.exe with a visible log?
Create a shortcut or batch file that starts the executable with -Log and the same ports you opened on the network. RocketWerkz specifically says that omitting -Log produces no visible log window, which makes diagnosing startup and binding failures much harder.
IcarusServer.exe -Log -PORT=17777 -QueryPort=27015Use the exact path where SteamCMD installed the current build. A batch file is convenient because it preserves the launch arguments and can be run again after maintenance. If the executable is not in the current directory, use its full quoted path, for example:
"C:IcarusServerIcarusServer.exe" -Log -PORT=17777 -QueryPort=27015Keep the log window open during initial setup. Look for the process to finish binding its ports and continue into a lobby or prospect. A window that closes immediately usually indicates a path, permission or startup error; the visible log identifies which one instead of failing silently.
Why must the server complete a first prospect or lobby?
The first boot can create the settings and save-tree directories only after the server reaches the initial prospect or lobby stage. Start it with the log enabled, wait for that stage to appear, then stop it cleanly before editing files.
- Launch the server using the shortcut or batch file.
- Wait until the log shows that the initial lobby or prospect has been created.
- Stop the process from the server console or by closing it normally; avoid killing the process during file creation.
- Browse to the generated configuration path and make your edits.
If you search for the configuration before completing this boot, you may conclude that the file is missing when it simply has not been generated yet.
Where is ServerSettings.ini and what should I change?
After first boot, edit ServerSettings.ini in the Windows dedicated-server save tree:
[ServerInstallDirectory]IcarusSavedConfigWindowsServerServerSettings.iniSet a server or join password and a separate administrator password. RocketWerkz says these values are not set by default but recommends setting them. Preserve the section header and existing keys; change values rather than replacing the file with an unstructured text document.
Safe configuration procedure
- Copy the original
ServerSettings.inito a dated backup folder. - Open the file in a plain-text editor.
- Keep the existing section header exactly as generated.
- Add or edit the password values and any other documented settings you intend to use.
- Save as plain text with the filename
ServerSettings.ini; check that your editor did not append.txt. - Restart the server and inspect the log for parsing or startup errors.
Passwords are separate from the network ports: a correct password cannot compensate for a blocked query port, and an open port does not remove the need for access control.
How do players join the dedicated server?
Restart the server after saving its settings and leave it running. Players use Icarus’s dedicated-server browser to locate the listing by server name and address, then connect with the configured join password.
- Give players the public address or hostname, not the host’s private LAN address when they are outside your network.
- Tell them the game and query port values if the server uses non-default settings.
- Provide the join password exactly as saved, including capitalization if the game treats it as case-sensitive.
- Keep the server process running while they search; a stopped process cannot appear or accept a connection.
If the listing is delayed, have a player refresh the browser after the server has completed startup. A listing requires the query service as well as the game service, so forwarding only UDP 17777 is insufficient.
How do I move an existing Icarus prospect to a dedicated server?
Copy the original prospect JSON without editing its filename or contents, then point the dedicated server at that filename. RocketWerkz’s New Frontiers manual warns that changing the file name or JSON data can corrupt the saved data.
Back up the local prospect first
On the computer that currently holds the prospect, locate:
%UserProfile%AppDataLocalIcarusSavedPlayerData{yourSteamIDNumber}Prospects{ProspectName.json}Copy the JSON to a separate backup location before moving anything. Keep this untouched copy until you have loaded and verified the dedicated-server world.
Prepare the dedicated-server save tree
- Complete the server’s first boot so its
Saveddirectories exist. - Place or edit
ServerSettings.iniinIcarusSavedConfigWindowsServer. - Set
LastProspectName=to the prospect filename without the.jsonextension. ForGame.json, useLastProspectName=Game. - Create this destination folder if it is not already present:
IcarusSavedPlayerDataDedicatedServerProspects - Copy the unedited prospect JSON into that
DedicatedServerProspectsfolder. - Start the server and verify in the log and game client that the intended prospect loads.
Do not rename the JSON to make it “match” a new server name, and do not open and resave it in an editor that might alter formatting or data. If the world fails to load, stop the server, restore the untouched backup, confirm that LastProspectName matches the filename stem exactly and check that the file is in the dedicated-server destination rather than the original player folder.
What should I check when the server is not visible?
Work from the process outward: confirm the executable is running, then verify launch arguments, firewall rules, router forwarding and the destination host address.
- No console output: add
-Logto the shortcut or batch command. Without it, RocketWerkz says there is no visible log window. - Process starts but does not list: confirm both UDP 17777 and UDP 27015 are allowed in the host firewall and forwarded to the current local IP.
- Port mismatch: compare
-PORT=and-QueryPort=in the launch command with every router and firewall rule. One changed value is enough to break discovery. - Settings file absent: run through the first prospect or lobby, stop the server, then look under
SavedConfigWindowsServer. - Players on the same LAN can join but internet players cannot: the router’s forwarding target may be wrong, the public address may have changed, or the internet service may block inbound traffic. Recheck the host’s current private address and router rule.
- World migration fails: restore the unedited JSON backup, verify the filename stem used by
LastProspectName, and confirm the destination isSavedPlayerDataDedicatedServerProspects.
Change one variable at a time and restart after configuration edits. This makes the log useful for identifying whether the failure is file-related, a port-binding issue or an external network problem.
Can I run an Icarus server on Linux?
The official setup path is Windows-focused. Community tooling describes Wine or Linux operation as an unofficial workaround, so it should be treated as unsupported by the canonical guide and rechecked after every game update.
If you nevertheless test a Linux deployment, keep a known-good Windows installation or backup, document the exact Wine and launch configuration, and expect updates to require renewed compatibility checks. Do not assume that a community workaround has the same behavior as the documented Windows executable.
Should I self-host or use a managed server?
Self-hosting gives you direct control and avoids a recurring hosting bill, while a managed Windows game-server provider shifts administration and network work to someone else. The right choice depends on who will maintain the machine and how important continuous availability is.
| Consideration | Self-hosted Windows machine | Managed server or Windows game-server VPS |
|---|---|---|
| Initial setup | Install SteamCMD, configure files, firewall and router forwarding yourself. | Provider may supply an image or panel, but you still need to confirm current Icarus support and complete game-specific setup. |
| Recurring cost | No game-server rental fee; you pay for electricity, hardware and your internet service. | Monthly charge; compare the current plan’s resource limits and renewal price. |
| Windows administration | You handle updates, permissions, restarts and troubleshooting. | Support may assist with the host, while Icarus configuration remains your responsibility. |
| Port forwarding | You must control the router and forward both UDP ports. | The provider normally supplies a public address and network rules; verify that both game and query ports are available. |
| Updates | Run SteamCMD and validate files on your schedule. | Check whether the provider offers automatic updates and whether they can be disabled for backup testing. |
| Backups | Design and test your own backup of settings and prospect JSON files. | Confirm retention, restore procedure and whether backups include the Icarus Saved tree. |
| Uptime and latency | Depends on your home power, internet connection and location. | Choose a region near players and verify the provider’s uptime terms and network location. |
| Capacity and support | Limited by your machine and connection; authoritative minimums are not published in the setup material. | Check the current build’s player support, CPU/RAM limits and the provider’s Icarus-specific support before paying. |
A provider is not a substitute for backups: retain your own copy of ServerSettings.ini and prospect files so you can recover from a failed update or accidental deletion.
What is the safest update and backup routine?
Stop the server, back up its save and configuration folders, update with SteamCMD, then restart and verify the log before inviting players back.
- Announce a maintenance window and stop the server cleanly.
- Copy
IcarusSavedConfigWindowsServerServerSettings.iniand the relevantPlayerDataprospect folder to storage outside the installation directory. - Run
app_update 2089300 validatein SteamCMD. - Launch with the same
-Log,-PORTand-QueryPortarguments. - Watch for startup, port-binding and prospect-load messages.
- Connect with a test account before opening the server to the full group.
Keep several dated backups rather than overwriting one copy. For migrated prospects, preserve the original JSON indefinitely until the dedicated version has been opened and checked in-game.
What are the essential Icarus server values to remember?
- Steam App ID: 2089300.
- Default game port: UDP 17777.
- Default query port: UDP 27015.
- Visible logs: include
-Login the launch command. - Configuration path:
IcarusSavedConfigWindowsServerServerSettings.ini. - Migration destination:
IcarusSavedPlayerDataDedicatedServerProspects. - Migration rule: keep the prospect JSON filename and contents unchanged, and make
LastProspectNamematch its filename stem.
Frequently Asked Questions
Do I need a separate Steam account to install the dedicated server?
No. The documented SteamCMD command uses login anonymous, and RocketWerkz says the dedicated-server installation does not require an Icarus license. You still need appropriate permission to install software and open network ports on the host.
Can I change the game and query ports later?
Yes. Set new values with -PORT= and -QueryPort=, then change the corresponding UDP forwarding and firewall rules together. Players must use the updated values, and a mismatch between any layer prevents discovery or connection.
How do I keep a prospect safe while experimenting with settings?
Stop the server and copy the prospect JSON and ServerSettings.ini to a location outside the installation folder before each major change. Keep the original JSON unedited, because RocketWerkz warns that changing its filename or data can corrupt the save.
Is a Linux Icarus dedicated server officially supported?
The canonical setup instructions are written for Windows. Wine/Linux methods are community workarounds, so compatibility can change after game updates and should not be treated as equivalent to the documented Windows deployment.
What should I verify with a hosting provider before renting a server?
Ask whether the current Icarus build is supported, which region and public ports are provided, how updates are applied, and whether backups include the Saved directory. Also confirm resource limits, restore steps and support coverage rather than relying on a generic game-server label.