Arma 3 Server Guide

Arma 3 is a realistic military tactical shooter and sandbox military simulation game developed by Bohemia Interactive. Running a dedicated server allows you to host custom missions, scenarios, and mods for your community.

🔌 Server Ports

Arma 3 servers require multiple ports for different functions. All ports must be forwarded and opened in your firewall for the server to function correctly.

Firewall Configuration

Configure your firewall to allow Arma 3 server traffic:

UFW (Ubuntu/Debian)

# Allow Arma 3 game port range
sudo ufw allow 2302:2306/udp comment 'Arma 3 Server'

# Or for custom port (example: 2402)
sudo ufw allow 2402:2406/udp comment 'Arma 3 Custom Port'

FirewallD (CentOS/RHEL)

# Add Arma 3 port range
sudo firewall-cmd --permanent --add-port=2302-2306/udp
sudo firewall-cmd --reload

# Verify rules
sudo firewall-cmd --list-ports

Windows Firewall

# Open PowerShell as Administrator
New-NetFirewallRule -DisplayName "Arma 3 Server" -Direction Inbound -Protocol UDP -LocalPort 2302-2306 -Action Allow

iptables (Generic Linux)

# Allow Arma 3 ports
sudo iptables -A INPUT -p udp -m udp --dport 2302:2306 -j ACCEPT
sudo iptables-save > /etc/iptables/rules.v4

Installation

Getting Your Server

To create an Arma 3 server:

1. Navigate to the Game Servers page
2. Find Arma 3 in the available games list
3. Select your preferred configuration (players, duration, location)
4. Add to cart and complete checkout
5. Your server will be automatically provisioned within 5-10 minutes

Server Files Structure

Your Arma 3 server includes these key directories:

• arma3server_x64.exe - Server executable (Windows)
• ./arma3server - Server executable (Linux)
• server.cfg - Main configuration file
• basic.cfg - Network and performance settings
• @mods/ - Mod installation directory
• mpmissions/ - Mission files folder
• BattlEye/ - Anti-cheat configuration

Configuration Files

server.cfg

The main server configuration file. Key settings:

// Server identity
hostname = "Your Arma 3 Server";
password = "";              // Join password (leave empty for public)
passwordAdmin = "adminpass"; // Admin password
serverCommandPassword = "rconpass"; // RCON password

// Server behavior
persistent = 1;             // Persistent missions
disableVoN = 0;            // Enable voice chat
vonCodecQuality = 10;      // Voice quality (0-30)
forceRotorLibSimulation = 0; // Advanced flight model

// Performance
maxPlayers = 64;
kickDuplicate = 1;
verifySignatures = 2;      // Mod signature verification
equalModRequired = 0;
allowedFilePatching = 0;

// Mission rotation
class Missions {
    class Mission1 {
        template = "yourMission.Altis";
        difficulty = "regular";
    };
};

basic.cfg

Network and bandwidth configuration:

// Bandwidth settings
MaxMsgSend = 256;
MaxSizeGuaranteed = 512;
MaxSizeNonguaranteed = 256;
MinBandwidth = 131072;      // 128 Kbps
MaxBandwidth = 10000000000; // Unlimited

// Client tuning
MinErrorToSend = 0.001;
MinErrorToSendNear = 0.01;
MaxCustomFileSize = 160000;

⚙️ Startup Parameters

Arma 3 server supports extensive command-line parameters for customization:

Windows Startup Command

arma3server_x64.exe -port=2302 -config=server.cfg -cfg=basic.cfg -profiles=SC -name=SC -mod=@mod1;@mod2 -serverMod=@serverMod1

Linux Startup Command

./arma3server -port=2302 -config=server.cfg -cfg=basic.cfg -profiles=SC -name=SC -mod=@mod1;@mod2 -serverMod=@serverMod1

Essential Parameters

Performance Parameters

// Recommended for performance
-limitFPS=50                  // Limit FPS to reduce CPU usage
-loadMissionToMemory          // Faster mission loading
-enableHT                     // Enable Hyper-Threading
-hugepages                    // Use huge memory pages (Linux)
-noSound                      // Disable sound on Linux
-world=empty                  // Start with empty world

Mods & Workshop Content

Installing Mods

Arma 3 supports Steam Workshop mods:

1. Subscribe to mods on Steam Workshop
2. Locate mod files in:
   C:\Program Files (x86)\Steam\steamapps\workshop\content\107410\
3. Copy mod folders to server @modname format
4. Add to startup parameters: -mod=@CBA_A3;@ACE;@RHSUSAF

Popular Mods

• CBA_A3 - Community Base Addons (required for many mods)
• ACE3 - Advanced Combat Environment (realism enhancement)
• RHS - Red Hammer Studios (weapons/vehicles)
• TFAR - Task Force Arrowhead Radio (realistic radio)
• CUP - Community Upgrade Project (maps/units)

🔧 Troubleshooting

Server Won't Start

Check Port Conflicts

Problem: Port 2302 already in use

Solution:

# Check if port is in use (Linux)
netstat -tulpn | grep 2302

# Check if port is in use (Windows PowerShell)
Get-NetTCPConnection -LocalPort 2302

# Use a different port
-port=2402

Missing Dependencies (Linux)

Problem: Library errors on Linux server

Solution:

# Install 32-bit libraries (Debian/Ubuntu)
sudo dpkg --add-architecture i386
sudo apt-get update
sudo apt-get install lib32gcc1 lib32stdc++6

# Install dependencies (CentOS/RHEL)
sudo yum install glibc.i686 libstdc++.i686

Configuration File Errors

Problem: Server.cfg syntax errors

Solution:

• Check for missing semicolons after each setting
• Validate mission class names match files in mpmissions/
• Remove comments with // from inside class definitions
• Check server logs in profiles folder for specific errors

Players Can't Connect

Firewall Blocking Connections

Problem: Server not visible in browser or players timeout

Solutions:

• Verify all UDP ports (2302-2306) are open in firewall
• Check router port forwarding if hosting at home
• Disable any VPN that might interfere with connections
• Test with telnet yourip 2302 (should get garbage response = port open)

Mod Signature Verification Failures

Problem: "File is not signed" errors

Solutions:

// In server.cfg, adjust verification level:
verifySignatures = 0;  // Disable verification (not recommended)
verifySignatures = 1;  // Only v1 signature check
verifySignatures = 2;  // Full signature verification (recommended)

// Or copy .bikey files to /keys/ folder
// Keys are usually in @modName/keys/*.bikey

Version Mismatch

Problem: "Wrong version" or "Bad version" errors

Solution:

• Update server using SteamCMD: steamcmd +login anonymous +app_update 233780 validate +quit
• Ensure all mods are updated to latest versions
• Clients must match server and mod versions exactly

Performance Issues

Low Server FPS

Problem: Server running below 20 FPS causing lag

Solutions:

• Reduce AI count in missions (AI are CPU-intensive)
• Use -limitFPS=50 to cap server FPS
• Enable -enableHT for hyper-threading support
• Optimize mission scripts (reduce frequent loops)
• Use server-side mods for performance (e.g., Advanced Rappelling)

High Desync

Problem: Players experience rubber-banding and desynchronization

Solutions:

// Adjust basic.cfg bandwidth settings:
MaxMsgSend = 512;          // Increase if high bandwidth
MaxSizeGuaranteed = 1024;
MinBandwidth = 262144;     // 256 Kbps minimum
MaxBandwidth = 10000000000; // Remove bandwidth cap

// In server.cfg:
maxPacketSize = 1400;      // Adjust for MTU

Memory Issues

Problem: Server crashes with "Out of memory" errors

Solutions:

• Use 64-bit server executable (arma3server_x64.exe)
• Add -malloc=system parameter (Windows)
• Use -hugepages on Linux for better memory management
• Reduce texture/terrain detail in missions
• Limit number of active mods

BattlEye Issues

BattlEye Kicks Players

Problem: Players kicked for script restrictions

Solution:

• Check BattlEye/scripts.txt for kicked script hash
• Add exception lines to appropriate .txt files
• Common files to modify: scripts.txt, publicvariable.txt, setvariable.txt
• Many mods come with BattlEye filters in their documentation

BattlEye Fails to Initialize

Problem: "BattlEye initialization failed" error

Solutions:

• Verify BattlEye port (2306 UDP) is open
• Check BattlEye folder permissions (needs write access)
• Temporarily disable antivirus and test
• Reinstall BattlEye files from server package

⚡ Performance Optimization

Server Configuration

// Recommended basic.cfg for performance
MaxMsgSend = 512;
MaxSizeGuaranteed = 1024;
MaxSizeNonguaranteed = 400;
MinBandwidth = 262144;
MaxBandwidth = 10000000000;
MinErrorToSend = 0.003;
MinErrorToSendNear = 0.02;

Startup Parameters for Performance

# Performance-optimized startup
-limitFPS=50 -enableHT -hugepages -loadMissionToMemory -noSound -world=empty

Mission Optimization

• Reduce AI count: Each AI unit consumes significant CPU
• Use caching: Cache AI groups when far from players
• Optimize scripts: Avoid while {true} loops, use scheduled scripts
• Limit view distance: Set reasonable viewDistance in mission
• Clean up objects: Delete dead bodies and destroyed vehicles

Hardware Recommendations

🔒 Security Best Practices

Password Protection

// In server.cfg
password = "join_password";        // Server join password
passwordAdmin = "secure_admin_pw";  // Admin password
serverCommandPassword = "rcon_pw";  // RCON password

BattlEye Configuration

• Always enable BattlEye for public servers
• Keep BattlEye files updated
• Review and update filter files regularly
• Monitor BattlEye/bans.txt for repeat offenders

Signature Verification

// Enforce mod signatures
verifySignatures = 2;     // Full verification
allowedFilePatching = 0;  // Disable file patching
onUnsignedData = "kick (_this select 0)";  // Kick on unsigned data

Admin Tools

• Use whitelist for admin slots in mission files
• Restrict RCON access to trusted IPs only
• Enable admin logging to track admin actions
• Consider server-side admin mods (e.g., InfiSTAR)

Regular Maintenance

• Review server logs daily for suspicious activity
• Keep server and mods updated to latest versions
• Backup configuration files and mission files regularly
• Monitor server resources (CPU, RAM, bandwidth)
• Test server changes in staging environment first

📚 Additional Resources

Official Documentation

• Bohemia Interactive Wiki - Dedicated Server
• BI Wiki - server.cfg Configuration
• BI Wiki - basic.cfg Configuration
• Bohemia Forums - Server Administration

Community Resources

• LinuxGSM - Arma 3 Server Script
• r/armadev - Server Development Community
• Official Arma Discord
• Steam Community Guides

🔌 Related Mods & Plugins

Popular server administration tools compatible with ARMA 3:

• BEC (BattlEye Extended Controls) - Server scheduler, auto-restart, and admin commands

Server Tools & Utilities

• Complete Startup Parameters List
• CBA_A3 - Community Base Addons
• ACE3 Mod
• TFAR - Task Force Radio

Performance Monitoring

• Server FPS Monitoring: Use diag_fps command in-game
• RPT Logs: Check profiles/*.rpt files for errors
• Network Stats: Use diag_log for network diagnostics

Documentation Version: 1.0 | Last Updated: November 10, 2025
Sources: Bohemia Interactive Wiki, LinuxGSM, Steam Community, r/armadev
For additional support, visit our Common Issues guide or contact support.