You can host an Arma 3 dedicated server on Windows or Linux by installing Bohemia Interactive’s free server package through SteamCMD, configuring a server profile, forwarding UDP ports 2302–2306, and launching the dedicated-server executable with a configuration file. The package uses Steam App ID 233780 and does not require the regular Arma 3 game to be purchased for the server machine. A reliable setup also needs a real public IPv4 connection: IPv6-only service and DS-Lite through an IPv6 tunnel are not supported by the documented server requirements.
This guide follows the official workflow: prepare the host, install or update the server with SteamCMD, create server.cfg, open the required firewall and router ports, test locally and externally, then add missions and mods one change at a time.
What do you need before making an Arma 3 server?
Prepare a Windows or Linux computer, enough CPU and memory for the intended player workload, storage for the server files and missions, and an internet connection that provides a real IPv4 address. The dedicated-server package itself is free and distributed through Steam Tools and SteamCMD under App ID 233780.
Hardware requirements
Bohemia Interactive’s dedicated-server page lists these baseline figures. They are not tied to a publication year, and they should be treated as workload guidance rather than a promise of a particular player count.
| Tier | CPU | Memory | Storage |
|---|---|---|---|
| Minimum listed | 2.4 GHz dual-core | 2 GB RAM | 32 GB HDD |
| Recommended | 3.5 GHz quad-core | 4 GB RAM | SSD |
Arma 3 simulation load varies with mission complexity, AI, scripts, terrain and the number of connected players. Start with the recommended specification when you can, and watch logs and system utilization after the first real sessions rather than assuming the minimum will suit every mission.
Operating system and network prerequisites
- Use a Windows or Linux host supported by the current dedicated-server package. The August 26, 2026 development update identifies version 2.22 and says 32-bit systems and Windows 7/8 support are deprecated, so confirm current platform support before deployment.
- Give the host a fixed address on your local network, or create a DHCP reservation, so router forwarding continues to point to the same machine.
- Confirm that your internet service supplies a real IPv4 address. The official documentation specifically warns that IPv6 and DS-Lite through an IPv6 tunnel are unsupported.
- Keep the server directory separate from the SteamCMD program directory. This makes updates, backups and recovery easier.
How do you install the Arma 3 dedicated server with SteamCMD?
SteamCMD downloads the server files and later applies patches. The critical identifier is App ID 233780; using the regular game App ID will not install the dedicated-server package.
- Download SteamCMD from Valve. Extract it into its own directory, separate from the directory where you want the Arma 3 server files.
- Choose a server directory. On Windows, an example is
C:Arma3Server. On Linux, an example is/opt/arma3server. Use a location with enough free space for the base files, missions, logs and mods. - Open SteamCMD and set the installation directory. Run the documented
force_install_dircommand for your chosen path before requesting the app. - Install and validate the package. Run:
app_update 233780 validateThe validate argument checks the downloaded installation as part of the update operation. Run the same command whenever you deliberately update the server, but stop the running server first so files are not changed while the executable is using them.
What should you do after SteamCMD finishes?
Verify that the dedicated-server executable and its supporting directories were created in the target folder. Do not launch a public session yet. First create the profile and configuration file, then perform a local connection test with the default, unmodded installation.
How do you create an Arma 3 server configuration file?
Create a text file such as server.cfg in the server directory or another location you can back up, then select it at launch with -config=server.cfg. The configuration reference is where you define the server identity and gameplay rules; the executable does not know your preferred mission cycle or access policy until you provide them.
Settings to decide in the configuration
- Hostname: the name players will see in the browser.
- Passwords: an administrator password and, if desired, a player password for a private session. Use a strong administrator password and do not reuse it elsewhere.
- Mission cycle: the order and selection of missions the server should offer.
- Player limit: the maximum number of connected players appropriate for the host’s CPU, memory and mission.
- Voting: who may vote and how mission or administrator decisions are handled.
- Difficulty: the difficulty profile that matches your group’s expectations.
- Logging: the level of information you need when diagnosing joins, mission changes or errors.
- BattlEye: whether the anti-cheat service is enabled and how it is administered.
Use the current Bohemia Interactive configuration reference for the exact directive names and syntax. Keep this file under versioned or dated backups so a later edit can be reversed without reinstalling the server.
How do you launch the server with a profile and configuration?
Use the -name parameter to choose a profile name and -config to select the configuration file. The official Linux example is:
./arma3server_x64 -name=server -config=server.cfgOn Windows, run the corresponding dedicated-server executable with the documented -name, -config and, when needed, -port options. A profile named server keeps profile data separate from the SteamCMD directory and gives you a predictable place to inspect runtime files.
Why use a separate profile?
The profile name is more than a label. It lets you keep configuration and profile data organized, and the official documentation supports separate profiles and configuration files when you operate multiple instances. Give each instance its own clearly named profile and configuration, then plan its ports so two processes never compete for the same socket.
Which ports does an Arma 3 server use?
The documented default incoming range is UDP 2302–2306. Forward the range to the server’s fixed LAN address and allow it through the host firewall. Each port has a distinct role:
| Port | Protocol | Documented function |
|---|---|---|
| 2302 | UDP | Game traffic |
| 2303 | UDP | Steam query |
| 2304 | UDP | Steam master |
| 2305 | UDP | Reserved voice-over-network (VON) traffic |
| 2306 | UDP | BattlEye functions |
BattlEye also needs outbound access to the documented BattlEye address on TCP and UDP 2344, and on TCP 2345. The official page lists those outbound destinations and protocols; apply them in the host firewall and any egress filter.
How do you configure the firewall and router?
Port forwarding only works when the router and the operating system firewall both allow the traffic. Complete these steps in order.
- Assign a stable LAN address. Reserve the server’s current address in your router or configure a fixed address on the host.
- Create inbound UDP rules. Allow UDP 2302, 2303, 2304, 2305 and 2306 on the host firewall, limited to the dedicated-server executable where your firewall supports application rules.
- Forward the same ports. On the router, forward UDP 2302–2306 from the internet to the host’s stable LAN address. Do not forward them to a changing DHCP address.
- Allow BattlEye egress. Permit outbound TCP and UDP 2344 and outbound TCP 2345 to the documented BattlEye destination.
- Check for conflicts. Ensure another game server or application is not already bound to the selected port range. If you run multiple Arma 3 instances, assign each one a non-conflicting port plan.
- Apply and record the rules. Save the router and firewall changes, note the host address and port assignments, and keep that record with your configuration backup.
How do you start and test the server?
Test in layers. A successful process start proves only that the executable can run; it does not prove that the router, query service or BattlEye path is reachable.
- Start without mods. Launch the executable with the profile and configuration parameters. Watch the console and log output for startup errors, configuration parsing failures or port-binding messages.
- Connect from the same network. Use a client on the local network to join the server. This verifies the installation and basic firewall path without depending on internet NAT behavior.
- Test from an external network. Use a client outside the home or office network, such as a separate internet connection. This checks the router forwarding and real IPv4 reachability.
- Check browser visibility. If direct joining works but the server is not listed, inspect UDP 2303, the host firewall and the router’s forwarding rule. The query path is separate from the game connection.
- Stop before changing files. Shut down the server cleanly before editing the configuration, installing updates or replacing mission files.
Troubleshooting by symptom
| Symptom | Checks to make | Corrective action |
|---|---|---|
| The process will not start | Executable path, profile name, configuration path and log output | Correct the launch command or configuration syntax, then restart from the server directory. |
| Local clients cannot join | Host firewall, selected port and another process using the port | Allow the dedicated-server executable and remove the port conflict. |
| Local join works, external join fails | Real IPv4 availability, router forwarding and fixed LAN address | Correct NAT forwarding or contact the ISP if the service uses IPv6-only or DS-Lite connectivity. |
| Server runs but is absent from the browser | UDP 2303 query forwarding and firewall rules | Allow and forward the query port, then restart and check the logs. |
| BattlEye-related errors appear | Inbound UDP 2306 and outbound TCP/UDP 2344 plus TCP 2345 | Permit the documented BattlEye traffic and verify that egress filtering is not blocking it. |
How do you add missions and mods safely?
Establish a known-good baseline before changing content. Start the unmodded server, connect successfully, run a mission, and save the relevant logs. Then add one mission or one mod set at a time.
Use a controlled order
- Stop the server and back up the working configuration, profile data and mission files.
- Add one mod set or mission collection.
- Make sure server and client versions are aligned.
- Restart and test locally before asking the whole group to connect.
- Test from an external network again if the change also affects startup or network behavior.
- If the change fails, remove only the newest addition and return to the last working backup.
The current development update warns that some data, including -mod=contact, is not fully multiplayer compatible. It also notes a known steam_appid.txt issue. Treat both as compatibility warnings: do not assume that content which loads in a local or single-player context will work correctly for a dedicated multiplayer session.
How do you update and maintain an Arma 3 server?
Maintenance is a repeatable stop, back up, update and test cycle rather than an occasional reinstall.
Safe update procedure
- Announce downtime and stop the running server.
- Back up
server.cfg, mission files, profile data and any mod installation notes. - Open SteamCMD and select the same server directory with
force_install_dir. - Run
app_update 233780 validate. - Review the update output and any changed log messages.
- Launch with the same profile and configuration parameters.
- Perform a local connection test, then an external test if the server is public.
Keep a dated backup before each update so you can restore configuration or mission data if a patch changes behavior. Review logs after every update and use a strong administrator password. Never edit or replace installation files while the server process is still running.
Operating more than one instance
Separate profiles and configuration files for each instance. Give each instance a clear name, its own mission and mod plan, and a non-conflicting port arrangement. Document which process owns each port so a restart does not accidentally launch two servers on the same endpoint.
Should you self-host or use managed Arma 3 hosting?
Self-hosting gives you direct control over files, ports and firewall policy, but you also own networking, uptime, updates, backups and security. Managed hosting can reduce routine operations work, while the provider may limit file access, mod choices or port customization. Compare the following before choosing.
| Decision factor | Self-hosting | Managed hosting |
|---|---|---|
| Monthly cost | You provide the hardware and internet service; ongoing cost depends on your existing equipment and connection. | You pay the host’s recurring plan charge. |
| CPU and RAM | You choose and upgrade the machine, subject to your budget and hardware. | The provider assigns an allocation tied to the selected plan. |
| Data-center location and latency | Latency follows your home or office location and ISP route. | You can usually select from the provider’s available locations. |
| SteamCMD updates | You schedule and run app_update 233780 validate. |
The provider may automate updates, but verify the policy and timing. |
| Mods and file access | You control the installation, configuration and mod files. | Control depends on the host’s file and mod policy. |
| Backups | You must create and test your own backups. | Backup coverage depends on the provider and plan; confirm retention. |
| DDoS protection | You arrange protection separately or rely on what your network provides. | Protection may be included or offered as an option; verify scope. |
| IPv4 availability | You must obtain a real IPv4 connection from your ISP. | Confirm that the service includes a reachable dedicated IPv4 address. |
| Firewall and port control | You control router forwarding and host-firewall rules. | The provider may restrict ports or require support changes. |
Choose self-hosting when you need unrestricted access to files and network settings and can maintain the system. Choose managed hosting when reducing operational work matters more than full control, provided the service meets the documented IPv4, mod and port requirements.
What changed in the current dedicated-server support?
Bohemia Interactive’s Spotrep #00121, reported August 26, 2026, identifies the current development version as 2.22 and again identifies App ID 233780 for the Steam Tools server package. It also says 32-bit and Windows 7/8 support are deprecated. Because supported operating systems, SteamCMD behavior, app availability and mod compatibility can change, check the current official documentation immediately before deploying or upgrading.
What is the final setup checklist?
- Host uses a supported Windows or Linux platform and meets the intended workload.
- SteamCMD is in a separate directory from the server files.
app_update 233780 validatecompleted successfully.- A backed-up configuration file defines hostname, passwords, missions, player limit, voting, difficulty, logging and BattlEye behavior.
- The server launches with a distinct profile through
-nameand the correct-configfile. - The host has a stable LAN address and a real IPv4 connection.
- UDP 2302–2306 are allowed and forwarded to the host.
- Outbound BattlEye traffic on TCP and UDP 2344 and TCP 2345 is allowed.
- An unmodded local test succeeds before external access is tested.
- Mods and missions are added incrementally with server and client versions aligned.
- Backups and logs are reviewed after every update.
Frequently Asked Questions
Can I run an Arma 3 dedicated server without buying Arma 3 for the server machine?
Yes. Bohemia Interactive states that the dedicated-server package is free and does not require the regular Arma 3 game to be purchased for the server package. Install the server package through SteamCMD with App ID 233780.
Will an IPv6-only or DS-Lite internet connection host the server?
No. The documented requirement is a real IPv4 connection, and the page warns that IPv6 and DS-Lite through an IPv6 tunnel are unsupported. Ask your ISP for a reachable IPv4 service or use a host that provides one.
Are the listed CPU and RAM figures guarantees for a specific player count?
No. The 2.4 GHz dual-core, 2 GB RAM and 32 GB HDD figures are listed minimums, while a 3.5 GHz quad-core, 4 GB RAM and SSD are recommended. Mission complexity, AI and scripts affect load, so monitor the server rather than translating the figures into a fixed player number.
Why can players connect directly but still fail to see the server in the browser?
The game connection and Steam query traffic use different ports. Check UDP 2303 specifically, along with the host firewall and router forwarding, because a server can accept a direct connection while its query response remains blocked.
What should I verify before installing a large mod collection?
Keep a working unmodded backup, then add one mod set at a time and align server and client versions. The current development update flags -mod=contact as not fully multiplayer compatible and mentions a known steam_appid.txt issue, so test every change before inviting the full group.