Arma 3 Server Setup

Your first hour: from a fresh install to a squad in the lobby

New game servers are normally live within 20 minutes of the order. These six moves turn a stock Arma 3 install into a server your unit can find, join and trust with its first op.

1. Log in to the game panelGo to cpdeluxe.com, sign in with your panel details and open the Arma 3 service. Start, Stop and the More menu sit together at the top of the page.
2. Stop the server firstArma 3 reads its config files once, at boot. Anything you save while it runs is ignored, so make stop, edit, save, start a reflex.
3. Name it and lock itOpen Configuration Files and edit server.cfg with the Config Editor. Fill in hostname, add a password if the server is for your unit only, and choose a long passwordAdmin. The server.cfg chapter explains the rest.
4. Choose what it playsIn the same file, type the mission's name into the template field. Bohemia's own scenarios work straight away; a unit mission goes into MPMissions first, as the missions chapter shows.
5. Start it and give it timePress Start. For the first 30 to 60 seconds the panel can show no CPU or memory use while a safety copy is made, and a heavy mod pack can stretch the boot to between 3 and 10 minutes.
6. Connect and pass on the addressIn Arma 3, open Multiplayer, choose Direct Connect and enter the IP and port from the panel's connection details, or search the browser for your server's name. Send the same address to your squad.

server.cfg line by line: the settings units actually change

Bohemia splits an Arma 3 server's setup between two files: server.cfg decides who gets in and what happens on the server, and basic.cfg tunes the network. In our panel both sit under Configuration Files, and server.cfg also has a form view in the Config Editor.

Name, passwords and the welcome message

Trust, signatures and anti-cheat

Votes and an empty server

Logs and time stamps

logFile = "server_console.log" copies the server console into a text file. The fuller record is the server's RPT log, and timeStampFormat (none by default, short or full) puts a time on each of its lines, which makes a crash far easier to trace. The panel's Log Viewer streams or downloads both.

New in update 2.22

Bohemia's update 2.22 (11 August 2026, SPOTREP #00120) added several server options worth knowing: idleFPSLimit caps the frame rate while the server is empty, timeStampFormatConsole puts times on console lines, logPlayerConnectionStates in the AdvancedOptions class logs each player's connection progress, and the -mpmissions= startup parameter points the server at another missions folder. The same update stopped the server locking its config file while running and clears the MPMissionsCache folder automatically once it passes 1GB.

Missions, rotation and difficulty: telling the server what to play

An Arma 3 server is only as good as the mission it runs. Missions are packed .pbo files in the MPMissions folder, and server.cfg decides which one loads, in what order, and how hard the AI fights back.

Naming a mission so the server finds it

A mission file is named after the mission and its terrain: RedDawn.Altis.pbo is a mission called RedDawn on Altis. Upload it to MPMissions with the File Manager or SFTP, then refer to it in server.cfg without the .pbo ending: template = "RedDawn.Altis";. Bohemia's own scenarios ship with the game and load by class name instead, such as MP_Warlords_01.Altis for Warlords or MP_ZGM_m11.Altis for the 48-player Zeus scenario.

A rotation instead of one mission

class Missions
{
  class Training
  {
    template = "Drill.Stratis";
    difficulty = "Regular";
  };
  class SundayOp
  {
    template = "RedDawn.Altis";
    difficulty = "Custom";
  };
};

The server works down the list and starts the next entry when a mission ends. A mission can also take its own lobby parameters in a class Params block inside its entry. Admins skip the queue with #missions, which opens the mission list for the admin to pick from.

Difficulty and the server profile

Each entry names a difficulty: Recruit, Regular, Veteran or Custom. Custom reads its options from the server's profile, <name>.Arma3Profile, where the name comes from the -name startup parameter (without one, Bohemia's default is player). That file is where you switch off third person, crosshairs or the map's markers, and set how sharp the AI is.

Want one rule for every mission? forcedDifficulty = "Custom"; in server.cfg enforces a single difficulty. Note the exception Bohemia documents: when you run a class Missions cycle, the difficulty in each entry wins over forcedDifficulty.

Workshop mods, keys and signatures without the headaches

Units live on mod packs: CBA_A3 underneath almost everything, then ACE, terrains and gear. The server has to load the same client mods as its players, hold a key for each, and keep server-only mods to itself.

1. Stop the serverMods download and register while the server is offline.
2. Open the Steam Workshop browserIt sits on the main page of the panel. Search for a mod by name, CBA_A3 for example.
3. Press InstallThe mod lands in a folder named after its Workshop ID, such as @450814997, and joins the -mod= line in Workshop.mods.
4. Start and testBoot the server and join with the same mods loaded in the Arma 3 Launcher. Add a big pack in stages, so a clash is easy to pin down.

-mod or -serverMod

Mods on -mod= must also be loaded by every player. Mods on -serverMod= run on the server only and are never asked of clients, the right home for admin tools and server scripts. In the Workshop.mods Easy Config Editor, moving a mod is a cut and paste of its @ID from one string to the other. Several mods in one string are separated by semicolons, with no spaces.

Keys and signatures

Every signed mod ships a .bikey, and each of its .pbo files carries a matching .bisign. The server's keys folder holds the keys it accepts, and with verifySignatures = 2 a player whose files are not signed by one of those keys cannot stay on. A vanilla server holds only Bohemia's own key. If one new mod suddenly blocks everyone, check that its key reached the keys folder.

Updating a pack safely

• Update from the Steam Workshop browser, or create a Workshop mod update task under Scheduled Tasks so the server keeps pace with what players download.
• Pick one installer and stay with it. Our guide warns that mixing the Workshop browser with the legacy downloader can have side effects.
• Before a big Arma 3 update, check each mod's Workshop page for recent activity. Mods that stopped being maintained are the usual reason a pack fails on patch day.
• Keep a written copy of your -mod= line. When something breaks, it is the quickest way back.

Official DLC and Creator DLC: who can join and how to load it

Arma 3's DLC rules are designed to keep units together. The server itself never needs to own anything; what matters is how each DLC treats players who do not.

Loading a Creator DLC

1. Install the dataStop the server, open the Mod Manager and install the Arma 3 Creator DLC package. It also adds a panel icon for keeping the Creator DLC up to date.
2. Add the codeIn Workshop.mods or Start.bat, add the DLC's code to the -mod= field: gm (Global Mobilization), vn (S.O.G. Prairie Fire), csla (CSLA Iron Curtain), ws (Western Sahara), spe (Spearhead 1944), rf (Reaction Forces) or EF (Expeditionary Forces).
3. Point the mission at itSet the template in server.cfg to a mission built for that DLC, either one that ships with it or a Multiplayer Scenario from the Workshop.
4. StartBoot the server and check the RPT log if the mission does not appear.

S.O.G. Prairie Fire is the one most units ask about. Its missions use the cam_lao_nam terrain, so a template reads like vn_coop_01.cam_lao_nam for the Eldest Son co-op or vn_warlords_01.cam_lao_nam for its Warlords mode. Our Creator DLC guide lists every template name it ships with.

The Headless Client: moving AI off the main server

In AI-heavy co-op the server's processor runs out long before its memory does. A Headless Client is a copy of Arma 3 with no screen that joins your server as a player and takes over AI groups, leaving the server free to handle players.

On the main server

1. Stop the main serverThen open server.cfg under Configuration Files.
2. Whitelist the Headless ClientPut the Headless Client's IP in both lines, inside the quotes: headlessClients[] = {"192.168.4.18"}; and localClient[] = {"192.168.4.18"};. The first lets it join; the second lifts its bandwidth limits.
3. Running several?List each IP, separated by commas, in both lines.

On the Headless Client server

1. Stop itOpen Configuration Files and edit its Start.bat.
2. Point it at your serverEnter the main server's IP in the -connect= field and, if the main server has a password, the same password in -password=.
3. Start bothStart the main server, then the Headless Client. It shows up in the player list like any other client.

The mission has to offer it a seat. In the Eden editor that is a unit with side Game Logic, class Virtual Entities, unit Headless Client, set to Playable and given a name; since 2.22 the server log warns when a Headless Client slot has no name, because it cannot be used. AI frameworks and many unit missions then pass groups across on their own. Bohemia's own launch line for a Headless Client is arma3server -client -connect=<ip> -password=<pass>, which our Start.bat fields fill in. With us a Headless Client is its own small server, ordered next to your main one; see Arma 3 Headless Client server.

Admin rights, server commands and BattlEye

Running an Arma 3 server well is mostly about the commands you type in chat and the anti-cheat you leave switched on.

Becoming admin

Open chat in game and type #login followed by the passwordAdmin from server.cfg. IDs listed in admins[] can log in without the password, and Bohemia treats both kinds of admin the same. Only one player can be logged in as admin at a time (RCon tools are separate), and #logout hands the rights back.

BattlEye and remote admin

With BattlEye = 1 in server.cfg, the anti-cheat runs on the server and players must run it too. The 64-bit server reads BEServer_x64.cfg in its BattlEye folder. Add RConPassword and RConPort there and a remote console tool can message, kick and ban without anyone in game. Bohemia's rule for the port: keep clear of the game port and the four after it (2302 to 2306 by default), so 2301 is a common choice. Since 2.22, the #mpmissions RCon command lists the missions on the server.

Memory, server FPS and network tuning on our Arma 3 plans

Arma 3 load comes from AI, scripts and mods far more than from the player count. Our plans differ by player slots and memory; the hardware is the same on all of them. These figures come from the order form, checked on 16 October 2026.

• Slots: 10 to 120 players, in steps of ten.
• Memory: 8GB comes free with the server; the order form adds 12GB, 16GB, 20GB, 24GB and 32GB as paid tiers.
• CPU: 5.0GHz included, with 5.2GHz+ and 5.6GHz+ upgrades, plus High or Realtime CPU priority.
• Storage: NVMe at 7,500MB/s with up to 100GB included; a 14,000MB/s option and up to 200GB for large terrain packs.

Read the server's own numbers

Log in as admin and type #monitor 10: every ten seconds the server reports its FPS, memory use and bandwidth. Server FPS is how many simulation frames it finishes each second, and Bohemia's network guide treats a server below 20 as overloaded, the point where AI turns sluggish and vehicles rubber-band. The -limitFPS startup parameter caps it (50 by default), and since update 2.20 an empty server drops to 30 on its own. Activity and Stats in the panel graphs memory over hours and days.

What actually helps

• Fewer active AI: spawn enemies in waves near the players instead of filling the map at mission start.
• Dynamic Simulation: a system mission makers switch on per object in the Eden editor; flagged AI and vehicles stop simulating while no player is near and wake as players approach.
• A Headless Client: gives the AI its own processor, the single biggest gain in large co-op.
• A lighter pack: every mod adds scripts the server runs on each frame.
• More memory for big terrains: large community maps and full packs are where 16GB and up earn their keep.
• Regular restarts: a long session collects bodies, wrecks and stray scripts; at least twice a day keeps things smooth.

basic.cfg and bandwidth

basic.cfg controls how much the server sends and how often. Bohemia's documented values start at MaxMsgSend = 128, MaxSizeGuaranteed = 512 and MaxSizeNonguaranteed = 256, and its advice is that the biggest gains come from MaxMsgSend and MinBandwidth (131072 in its example), both raised together when the server is not using the bandwidth it has. Push MaxMsgSend too high for the CPU and you get desync instead, so change one value at a time and watch #monitor.

Memory, slots and CPU priority change in the client area under Services, My Services, your server, then Upgrade/Downgrade options. An upgrade raises an invoice for the difference, and a restart after payment applies it.

Restarts, warnings, updates and backups

A server that restarts on a timetable, warns players first and keeps backups never surprises the unit mid-op. Everything here runs from the panel's Scheduled Tasks.

A restart every six hours

1. Create the taskOpen Scheduled Tasks, create a task and choose Scheduled Restart. Call it something clear, like 6 Hour Restart.
2. Set the first runPick the date and time of the next restart. The panel works in server time, so compare it with your own clock; the time it suggests is server time plus about ten minutes.
3. Repeat itRecur every 1 day, tick Repeat task, repeat every 6 hours for 24 hours, then save. Change the 6 to any interval that suits your op schedule.

Warnings with the Server Messages plugin

Install Server Messages from the Mod Manager's tools section, then edit messages.cfg under Configuration Files. Each line holds a time, the message and a repeat rule, separated by a tilde:

17:45:00~Restart in 15m~no-loop
11:50:00~Restart in 10m~loop-6

• Messages use the 24 hour clock on server time, while the restart task is set on a 12 hour clock. Line the two up carefully.
• no-loop shows a message once; loop-6 repeats it every six hours.
• No spaces at the end of a line and no empty lines, or the messages stop showing.
• Keep colons and the tilde out of the message text itself: the plugin can crash on special characters.

Game updates and backups

When Bohemia ships an update, stop the server, press Steam Update and wait for the window to finish before starting again; a Steam Update task can do the same on a timer. If an update keeps failing, deleting the steamapps folder from the server root forces a full check next time. Take a backup first: Backup Server makes one on demand, a Scheduled Backup task makes them on a timetable, and Restore Server rolls back to the date you pick. A Reinstall resets the files, and a MySQL database if you use one, but leaves your backups alone.

Exile, Altis Life and King of the Hill: modes with their own server type

Some of Arma 3's best-known communities run on modes that need a database, a map pack or their own config. We sell those as separate server types, set up for the mode from the start, and their guides sit in the same Arma 3 section of our knowledge base.

Adding a map to an Exile server

1. Start cleanInstall the map on a server without other mods and test it first. Some mods do not get on with some maps, and a clean start shows which.
2. Download the terrain modsWith the server stopped, fetch CUP Terrains Core (583496184) and, for the Chernarus family, CUP Terrains Maps (583544987), plus the map's own mod where one exists, then load them on the -mod= line in Start.bat.
3. Install the map packUse the Map Packs button to install the matching pack.
4. Select the missionEdit config.cfg and choose the mission, such as Exile.Chernarus_Isles, from the template dropdown. Start the server.

On King of the Hill, the Creator DLC package from the Mod Manager also unlocks two Western Sahara missions on the Sefrou-Ramal terrain, a standard and an infantry-only version. Re-save config.cpp and run the settings compiler after switching, so the new map gets its default values.

When something breaks: the fixes we reach for first

Most Arma 3 tickets come down to a handful of causes. Work down this list before you reinstall anything.

• The server is not in the multiplayer browserGive a modded server up to 10 minutes after Start. Then use Direct Connect with the IP and port from the panel; if that works, the server is up and the browser has not caught up. Steam's server favourites, using the query address, are another way to check.
• The Launcher shows only part of the mod listLong mod lists are cut short in the server's Steam data. Bohemia's steamProtocolMaxDataSize setting in server.cfg (1024 by default) raises the limit; go up in small steps, as very large values can exceed the network's packet size.
• Players are kicked for unsigned or modified filesA key is missing or a player runs a different version of a mod. Check that every -mod= entry has its .bikey in the keys folder and that players have updated their Workshop subscriptions.
• The mission fails to load or the lobby is emptyThe mission was probably made with a mod or DLC the server does not load, or its template name is misspelt. The RPT log in Log Viewer names the missing addon or file.
• Nobody can join after an Arma 3 updateThe server is still on the old build. Stop it, run Steam Update, update the mods that changed and start again.
• Config changes do nothingThey were saved while the server was running, so the server kept its old settings. Stop it, save again, start it.
• The Headless Client connects but the AI stays putThe mission or its AI scripts do not hand groups over. Check the mission has a playable Headless Client entity and that its AI framework supports one.
• Restart warnings never appearLook for trailing spaces, empty lines or a colon inside the message text in messages.cfg, and check that the times are server time on the 24 hour clock.
• Mods behave oddly after a mixed installMods added with both the Workshop browser and the legacy downloader can collide. Keep to one installer and reinstall the affected mods with it.
• Zero CPU and memory right after StartNormal for 30 to 60 seconds while the panel takes its safety copy.
• Lag or desync late in the eveningRestart at least twice a day, and look at AI counts with #monitor. A Headless Client or a lighter mission usually helps more than extra memory.

Self-host or rent: what running your own takes

Bohemia gives the dedicated server away free as the Arma 3 Server tool on Steam, for Windows and Linux. It runs happily on a spare machine; the question is who looks after it.

Self-hosting means installing the server with SteamCMD (app 233780), signed in with a Steam account (Bohemia suggests a separate one, which does not need to own Arma 3), then starting arma3server_x64 with your -config, -cfg and -profiles paths and forwarding the ports. Bohemia lists them all as UDP: 2302 for the game (voice runs through it too), 2303 for Steam queries, 2304 for Steam traffic, 2305 reserved and 2306 for BattlEye. The server does not support IPv6.

A small group running Zeus nights together can host at home without trouble. Once the unit trains on a timetable, runs a growing mod pack or wants the server up when the admin is away, renting buys back the evenings. Plans are on our Arma 3 Server Hosting page.