{"id":3780,"date":"2026-10-27T17:09:47","date_gmt":"2026-10-27T14:09:47","guid":{"rendered":"https:\/\/gameteam.io\/blog\/arma-3-dedicated-server-guide\/"},"modified":"2026-10-27T17:09:47","modified_gmt":"2026-10-27T14:09:47","slug":"arma-3-dedicated-server-guide","status":"publish","type":"post","link":"https:\/\/gameteam.io\/blog\/arma-3-dedicated-server-guide\/","title":{"rendered":"Arma 3 Dedicated Server: Setup, Requirements, Ports, Mods and Fixes"},"content":{"rendered":"

An Arma 3 dedicated server is a separate, free copy of Arma 3 that runs a mission on its own, with no player sitting at the host PC.<\/strong> You install it with SteamCMD (app 233780) on Windows or Linux, give it 4\u20138 GB of RAM and the fastest CPU core you have, open UDP ports 2302\u20132306, and control it from a server.cfg<\/code> file. This guide covers every step \u2014 requirements, install, config, mods, missions, admin \u2014 and then the problems people actually hit, like a server not showing up for friends.<\/p>\n

Dedicated server or hosting from the game?<\/h2>\n

Arma 3 can host a multiplayer game straight from the client, or run as a dedicated server. Hosting from the game is quicker for one evening with friends; a dedicated server is what you want for a unit, a persistent mission like Antistasi, or anything with heavy AI. The table shows the difference at a glance.<\/p>\n\n\n\n\n\n\n\n\n\n
<\/th>\nHost from the game (non-dedicated)<\/th>\nArma 3 dedicated server<\/th>\n<\/tr>\n<\/thead>\n
Runs when the host is offline<\/td>\nNo \u2014 the server closes when you quit<\/td>\nYes<\/td>\n<\/tr>\n
Performance<\/td>\nYour PC renders the game and<\/em> simulates the mission<\/td>\nAll of the CPU goes to the mission and AI<\/td>\n<\/tr>\n
Config<\/td>\nMenu options<\/td>\nFull control in server.cfg<\/code>, basic.cfg<\/code> and the profile<\/td>\n<\/tr>\n
Mods<\/td>\nWhatever you load in the launcher<\/td>\n-mod=<\/code> and server-only -serverMod=<\/code><\/td>\n<\/tr>\n
Best for<\/td>\nA quick co-op night<\/td>\nUnits, persistent missions, public servers<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

How to host a server for friends from the game<\/h3>\n
    \n
  1. Load the mods everyone will use in the Arma 3 Launcher, then start the game.<\/li>\n
  2. Open Multiplayer \u2192 Server Browser<\/em> and choose the Host Server<\/em> tab.<\/li>\n
  3. Set a server name, set Host to Internet<\/em>, add a password, tick UPnP<\/em> and click Host Server<\/em>.<\/li>\n
  4. Pick a map and mission, then click Play<\/em>. Friends find it by name in the server browser.<\/li>\n<\/ol>\n

    If UPnP doesn’t work, forward UDP 2302\u20132306 to your PC by hand (see ports<\/a>) \u2014 but don’t use UPnP and manual forwarding at the same time, they conflict. Only the host needs to forward ports. If you can’t forward at all, a VPN tool like Hamachi works as a workaround, as long as every player installs the same tool and joins the same network.<\/p>\n

    Arma 3 dedicated server requirements<\/h2>\n

    An Arma 3 server is limited by the CPU first. The server binary can use more than one core, but the mission and AI simulation lean on one fast core, so a high clock speed beats a high core count. A server does not need a graphics card. These are the numbers to plan around:<\/p>\n\n\n\n\n\n\n\n\n\n
    <\/th>\nBare minimum<\/th>\nRecommended<\/th>\n<\/tr>\n<\/thead>\n
    CPU<\/td>\n2.4 GHz dual-core, 64-bit x86<\/td>\n3.5 GHz+ quad-core<\/td>\n<\/tr>\n
    RAM<\/td>\n2 GB<\/td>\n4\u20138 GB; add about 2 GB per headless client<\/td>\n<\/tr>\n
    Storage<\/td>\n32 GB<\/td>\n50 GB+ SSD \u2014 mods add a lot<\/td>\n<\/tr>\n
    Network<\/td>\n0.5 Mbit\/s upload per player<\/td>\n1\u20135 Mbit\/s per player, real IPv4<\/td>\n<\/tr>\n
    OS<\/td>\n64-bit Windows or Linux<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Two catches. Arma 3 servers don’t support IPv6 or DS-Lite tunnels, so you need a real public IPv4 address. And on CPUs with efficiency cores, performance can tank if the server lands on the slow cores; the -cpuCount<\/code> or -cpuAffinity<\/code> startup parameters keep it on the fast ones. Server RAM is mostly a modpack question: a vanilla Zeus night fits in 4 GB, while Antistasi or Exile with a large mod list wants the upper end of 8 GB.<\/p>\n

    How to set up an Arma 3 dedicated server<\/h2>\n

    Step 1: Download the server with SteamCMD<\/h3>\n

    The Arma 3 dedicated server download is Steam app ID (AppID) 233780<\/strong>, separate from the game (107410). Unlike many games, it can’t be installed with SteamCMD’s anonymous login: you need a real Steam account with Steam Guard turned off. That account doesn’t have to own Arma 3, so make a separate account just for servers.<\/p>\n

    On Windows, install SteamCMD to a folder like C:\\SteamCMD<\/code> and run:<\/p>\n

    steamcmd +force_install_dir C:\\arma3server +login yoursteamaccount +app_update 233780 validate +quit<\/code><\/pre>\n
    On Linux (Ubuntu or Debian), install SteamCMD from your package manager, create a non-root user for the server, and run the same command with a Linux path:<\/p>\n
    steamcmd +force_install_dir \/home\/arma3\/server +login yoursteamaccount +app_update 233780 validate +quit<\/code><\/pre>\n
    The same command updates the server later. You’ll get arma3server_x64.exe<\/code> on Windows and arma3server_x64<\/code> on Linux (plus 32-bit versions you can ignore).<\/p>\n
    Step 2: Create server.cfg<\/h3>\n
    The server doesn’t ship with a server.cfg<\/code> \u2014 you make the file yourself. Create it next to the executable and start with:<\/p>\n
    hostname = \"My Arma 3 Server\";\npassword = \"squad-only\";\npasswordAdmin = \"something-long-and-private\";\nmaxPlayers = 32;\nmotd[] = {\"Welcome to the server\", \"TeamSpeak and rules on our Discord\"};\nmotdInterval = 30;\npersistent = 1;\nverifySignatures = 2;\nBattlEye = 1;\nkickDuplicate = 1;\nvoteThreshold = 0.33;\nvoteMissionPlayers = 1;<\/code><\/pre>\n
    Lines starting with \/\/<\/code> are comments. Every setting line ends with a semicolon. The settings table<\/a> below explains what each one does.<\/p>\n
    Step 3: Write the start command<\/h3>\n
    On Windows, save this as start_server.bat<\/code> in the server folder:<\/p>\n
    arma3server_x64.exe -port=2302 -config=server.cfg -cfg=basic.cfg -profiles=profiles -name=server -world=empty -mod=@cba_a3;@ace<\/code><\/pre>\n
    On Linux, the same line goes in a shell script \u2014 quote the mod list, because a semicolon ends a shell command:<\/p>\n
    .\/arma3server_x64 -port=2302 -config=server.cfg -cfg=basic.cfg -profiles=profiles -name=server -world=empty \"-mod=@cba_a3;@ace\"<\/code><\/pre>\n
    Leave out -mod=<\/code> for a vanilla server and -cfg=basic.cfg<\/code> until you’ve made that file.<\/p>\n
    Step 4: Open the ports and start it<\/h3>\n
    Forward the ports in the ports table<\/a> on your router, allow them through the firewall (on Linux: sudo ufw allow 2302:2306\/udp<\/code>), then run the script. Join from the game to check it works, then hand the address to your friends.<\/p>\n
    Server tools if you’d rather click than type<\/h3>\n
    On Windows, community tools like FASTER and the older TADST put the startup parameters, the mod list and server.cfg<\/code> behind a window, which helps if you run several setups. On Linux, LinuxGSM can install and run the server and keep it updated. A server manager doesn’t change the files underneath, so knowing what server.cfg<\/code> does still pays off. Or skip running anything yourself with Arma 3 server hosting<\/a>.<\/p>\n
    Arma 3 server config: server.cfg, basic.cfg and the profile<\/span><\/h2>\n
    An Arma 3 server reads three files. server.cfg<\/code> (loaded with -config=<\/code>) holds the name, passwords, security and the mission cycle. basic.cfg<\/code> (loaded with -cfg=<\/code>) tunes bandwidth and packet sizes. The server profile, server.Arma3Profile<\/code> in the profiles folder, holds the difficulty settings. Most owners only ever touch the first.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
    server.cfg setting<\/th>\nWhat it does<\/th>\n<\/tr>\n<\/thead>\n
    hostname<\/code><\/td>\nName in the server browser<\/td>\n<\/tr>\n
    password<\/code><\/td>\nJoin password; leave it out for a public server<\/td>\n<\/tr>\n
    passwordAdmin<\/code><\/td>\nPassword for #login<\/code><\/td>\n<\/tr>\n
    admins[]<\/code><\/td>\nSteam64 IDs that can log in as admin without the password<\/td>\n<\/tr>\n
    maxPlayers<\/code><\/td>\nSlots; the real limit is AI and scripting load<\/td>\n<\/tr>\n
    verifySignatures<\/code><\/td>\n2<\/code> checks every client addon against the keys folder<\/td>\n<\/tr>\n
    BattlEye<\/code><\/td>\n1<\/code> on, 0<\/code> off<\/td>\n<\/tr>\n
    persistent<\/code><\/td>\n1<\/code> keeps the mission running with nobody on<\/td>\n<\/tr>\n
    disableVoN<\/code><\/td>\n1<\/code> turns off in-game voice<\/td>\n<\/tr>\n
    headlessClients[]<\/code> \/ localClient[]<\/code><\/td>\nIP addresses allowed to connect as headless clients<\/td>\n<\/tr>\n
    class Missions<\/code><\/td>\nThe mission cycle (next section)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Mission files and the mission cycle<\/h3>\n
    Missions are .pbo<\/code> files named MissionName.MapName.pbo<\/code>. Put them in the mpmissions<\/code> folder, then list them in server.cfg<\/code> \u2014 without that, a fresh server sits on an empty rotation and waits for an admin to pick one:<\/p>\n
    class Missions\n{\n    class Mission1\n    {\n        template = MP_Marksmen_01.Altis;\n        difficulty = \"veteran\";\n        class Params {};\n    };\n};<\/code><\/pre>\n
    template<\/code> is the file name without .pbo<\/code>. Add more class<\/code> blocks for a rotation. Mission parameters (the options a mission offers in its lobby) go inside class Params<\/code>, using the parameter names that mission defines. Add -autoInit<\/code> to the start command (it only works with persistent = 1;<\/code>) and the server starts the first mission on boot instead of waiting for a player.<\/p>\n
    Custom difficulty settings<\/h3>\n
    The built-in difficulties (Recruit, Regular, Veteran) need no setup. For a custom difficulty \u2014 no crosshair, no third person, no name tags \u2014 add a CustomDifficulty<\/code> class to server.Arma3Profile<\/code>:<\/p>\n
    class DifficultyPresets\n{\n    class CustomDifficulty\n    {\n        class Options\n        {\n            groupIndicators = 0;\n            friendlyTags = 0;\n            enemyTags = 0;\n            weaponCrosshair = 0;\n            thirdPersonView = 0;   \/\/ 0 off, 1 on, 2 vehicles only\n            mapContent = 0;\n        };\n        aiLevelPreset = 3;         \/\/ 3 = use CustomAILevel\n    };\n    class CustomAILevel\n    {\n        skillAI = 0.5;\n        precisionAI = 0.5;\n    };\n};<\/code><\/pre>\n
    Then set difficulty = \"Custom\";<\/code> on the mission in class Missions<\/code>.<\/p>\n
    Performance settings<\/h3>\n
    Server performance is measured in server FPS \u2014 log in as admin and type #monitor 5<\/code> to see it. The usual levers, in order: fewer AI and better-written missions, a headless client that takes the AI off the main server, and only then basic.cfg<\/code> values like MaxMsgSend<\/code>, MinBandwidth<\/code> and MaxBandwidth<\/code>. -limitFPS<\/code> caps how many simulation cycles the server runs per second, and -loadMissionToMemory<\/code> keeps the mission pre-processed in memory after the first client downloads it, which saves server CPU for the next ones. A headless client is a second copy of Arma 3 started with -client -connect=127.0.0.1 -port=2302<\/code> and listed in headlessClients[]<\/code>; the mission has to support it.<\/p>\n
    How to add mods to an Arma 3 dedicated server<\/h2>\n
    Arma 3 server mods load from @folders<\/code> next to the executable. Client mods go on -mod=<\/code> and every player must run the same ones; server-only mods go on -serverMod=<\/code> and players don’t need them. Every client mod also ships a .bikey<\/code> file that must go into the server’s keys<\/code> folder, or verifySignatures<\/code> kicks everyone running it.<\/p>\n
      \n
    1. Download the Workshop mods.<\/strong> Subscribe in the Arma 3 Launcher on your own PC. Steam saves them under steamapps\/workshop\/content\/107410\/<mod ID><\/code>. Downloading Workshop mods straight on the server through SteamCMD only works if the server’s Steam account owns Arma 3.<\/li>\n
    2. Copy them to the server<\/strong> as named folders, for example @cba_a3<\/code> and @ace<\/code>.<\/li>\n
    3. On Linux, make everything lowercase<\/strong> \u2014 the folder names and the addons<\/code> folder inside each mod. Uppercase letters stop the server from loading them.<\/li>\n
    4. Copy each mod’s .bikey<\/strong> from its keys<\/code> (or key<\/code>) folder into the server’s keys<\/code> folder.<\/li>\n
    5. Add the folders to the start command<\/strong>: -mod=@cba_a3;@ace<\/code>. Load dependencies (CBA first) before the mods that need them.<\/li>\n<\/ol>\n
      Arma 3 Launcher presets export as an HTML file, which some server tools can read to build the mod list for you. Keep the preset in your unit’s Discord so everyone loads the exact same set.<\/p>\n
      DLC and Creator DLC on a server<\/h3>\n
      Creator DLCs like S.O.G. Prairie Fire, Spearhead 1944 (WW2) and Western Sahara come with the server’s creatordlc<\/code> Steam branch, which installs the files every Creator DLC needs: install with app_update 233780 -beta creatordlc validate<\/code>, then load them like a mod by their folder name, for example -mod=vn<\/code> for Prairie Fire or -mod=spe<\/code> for Spearhead.<\/p>\n
      Popular server types you can run<\/h2>\n
      Most of the best Arma 3 servers people look for \u2014 modded or vanilla \u2014 are a mission plus a mod list. Any of these run on your own dedicated server once you have their files:<\/p>\n