Install a Arma 3 server

Step-by-step installation

1. 1

   Prepare a 64-bit machine with a fast single-thread CPU (the server depends on it heavily).

2. 2

   Install SteamCMD and download app 233780 with an anonymous login.

3. 3

   Generate server.cfg and basic.cfg with the site's tool, then drop your missions (.pbo) into mpmissions.

4. 4

   Start arma3server_x64 with -config, -cfg, -port and -autoInit.

5. 5

   Open UDP ports 2302 to 2306 (system firewall, provider, router).

6. 6

   For mods, download them from the Workshop with a Steam account that owns Arma 3 and copy them as @folders.

7. 7

   Create a systemd service (Linux) or a scheduled task (Windows).

8. 8

   Schedule updates, profile backups and a daily restart.

9. 9

   Test from outside and list the server on game-rank.com.

Requirements

Systems: 64-bit Windows and Linux. The Arma 3 engine is mostly single-threaded: favour single-core speed over core count, 4 to 8 GB of RAM (more with large mods or heavy missions), an SSD and good upstream bandwidth. No account is needed for the server; a Steam account that owns Arma 3 is only required to download Workshop mods. These figures are indicative, not official minimums.

Local install (Windows)

With SteamCMD (Valve), install the server and start it with your configuration files; in the game use Multiplayer > Server browser > Direct connect: 127.0.0.1.

steamcmd.exe +force_install_dir C:\Arma3Server +login anonymous +app_update 233780 validate +quit

cd /d C:\Arma3Server
arma3server_x64.exe -name=server -port=2302 -config=server.cfg -cfg=basic.cfg -profiles=profiles -world=empty -autoInit

Install on a Linux VPS / dedicated server

On Ubuntu/Debian, create a non-root user and install SteamCMD (on Debian, enable “non-free” first).

sudo apt update && sudo apt install -y software-properties-common
sudo add-apt-repository -y multiverse && sudo dpkg --add-architecture i386 && sudo apt update
sudo apt install -y steamcmd lib32gcc-s1 ca-certificates
sudo adduser --disabled-password --gecos "" arma3

First start

Download the server as the dedicated user, add server.cfg, basic.cfg and your missions in mpmissions, then start. -world=empty and -autoInit load the first mission of server.cfg (persistent = 1 required).

sudo -iu arma3
mkdir -p ~/server && /usr/games/steamcmd +force_install_dir ~/server +login anonymous +app_update 233780 validate +quit
cd ~/server && mkdir -p profiles
./arma3server_x64 -name=server -port=2302 -config=server.cfg -cfg=basic.cfg -profiles=profiles -world=empty -autoInit

Ports to open

The default game port is 2302 (-port=); the following ports are used for Steam queries, master traffic and BattlEye (UDP range 2302 to 2306 per the Bohemia Interactive wiki). If you change -port, shift the whole range.

• 2302/UDP — game
• 2303–2305/UDP — Steam queries and master traffic
• 2306/UDP — BattlEye

Linux firewall (ufw)

sudo ufw allow 2302:2306/udp
sudo ufw status verbose

Windows firewall (netsh)

netsh advfirewall firewall add rule name="Arma 3 2302-2306 UDP" dir=in action=allow protocol=UDP localport=2302-2306

Provider firewall and home router (NAT)

At OVH, Hetzner, Scaleway and similar providers, also open the same ports in the provider firewall (security group / panel firewall): it filters before the machine. For home hosting, create a NAT (port forward) rule on your router for each port to the server's local IP, with the right protocol. Test from outside (mobile network); never expose administration ports (RCON) without a strong password.

Automatic start (systemd)

Create start.sh (see the site's launch tool), then this service in /etc/systemd/system/arma3.service and run: sudo systemctl daemon-reload && sudo systemctl enable --now arma3. On Windows, use a scheduled task at startup that runs your start.bat.

[Unit]
Description=Arma 3 server
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=arma3
WorkingDirectory=/home/arma3/server
ExecStart=/home/arma3/server/start.sh
Restart=on-failure
RestartSec=15
LimitNOFILE=100000

[Install]
WantedBy=multi-user.target

Updates

Stop the service, rerun app_update, update your Workshop mods (with a Steam account that owns Arma 3), then restart. Clients must be on the same version as the server.

sudo systemctl stop arma3
sudo -u arma3 /usr/games/steamcmd +force_install_dir /home/arma3/server +login anonymous +app_update 233780 validate +quit
sudo systemctl start arma3

Backups and scheduled restarts

Back up the profiles folder (profile, .Arma3Profile files, persistent mission saves) along with server.cfg and basic.cfg; schedule a daily restart (here 05:00, backup at 04:55).

# crontab -e (root)
55 4 * * * tar czf /var/backups/arma3-$(date +\%F).tgz -C /home/arma3/server profiles server.cfg basic.cfg
0 5 * * * systemctl restart arma3

Listing and finding your server

Once the server is reachable from outside, add it on game-rank.com/jeux/arma-3 (the owner's site) so players can discover it.

Troubleshooting

• Server missing from the list: UDP ports 2302 to 2306 closed (firewall, provider, NAT), or a password set in server.cfg — test with direct connect.
• “Signature check failed” or players kicked: the server's mod doesn't match the client's (version, missing .bikey in the keys folder).
• Mission not loading: PBO name without .Map suffix, mission.sqm outside the root, or a server.cfg template that differs from the file name (without .pbo).
• Server lag: CPU too slow in single-thread, too much AI/scripts; consider headless clients and check basic.cfg.
• Server exits immediately: syntax error in server.cfg (missing semicolon or quote) — check the .rpt file in the profiles folder.

Frequently asked questions

Do I need to own Arma 3 to host?

Not for the server itself (app 233780, anonymous login). Yes to download Workshop mods, which require an account that owns the game.

Which ports should I open?

UDP 2302 to 2306 for the default setup (-port=2302).

How do I install mods on the server?

Put each mod in an @name folder, copy its .bikey files into the server's keys folder, then list it in -mod= (or -serverMod= if server-only).

Why schedule restarts?

A daily restart frees memory and avoids drift in long persistent sessions; do it off-peak after a backup.