The Arma Reforger dedicated server tool is a free, separate app — Arma Reforger Server, Steam app 1874900 — that runs a Reforger scenario on its own, 24/7, for up to 128 players. You install it with SteamCMD on Windows or Linux without owning the game, give it 4–8 GB of RAM, open UDP port 2001, and describe the whole server in one config.json file: name, scenario, mods, platforms. This guide covers the setup step by step, then mods, crossplay, admin commands and the errors people actually hit, like “server unreachable”.
Dedicated server, player-hosted server or a rented one?
Reforger gives you three ways to play with friends. A player-hosted session runs from your game client and ends when you leave. A dedicated server is the separate tool in this guide: it keeps running without you, can take a full 128-player lobby and loads any Workshop mods you list. A rented server, like Arma Reforger server hosting on GameTeam, is the same dedicated tool on someone else’s hardware. The dedicated server software only exists for Windows and Linux, so Xbox and PS5 players can join one but can’t run one.
| Player-hosted | Dedicated server | |
|---|---|---|
| Runs when the host is offline | No | Yes |
| How many players | Limited by the host’s PC and connection | Up to 128 (maxPlayers) |
| Config | In-game options | Everything in config.json |
| Mods | What the host has loaded | Listed by mod ID; players download them on join |
| Persistence | Ends with the session | Can save and load progress across restarts |
Arma Reforger dedicated server requirements
Reforger’s server is lighter than Arma 3’s at the same player count, but it scales with the scenario, the AI and the mod list. The biggest surprise is CPU: with no frame cap, the server can use 300–600% CPU under load (three to six cores’ worth), so always start it with -maxFPS.
| Minimum | Recommended | |
|---|---|---|
| CPU | Recent 64-bit x86 (Intel or AMD), no ARM | Cap the server FPS with -maxFPS |
| RAM | About 3.3 GB | 6–8 GB, more for big modpacks |
| Storage | 5 GB | 7–10 GB plus your mods |
| OS | 64-bit Windows or 64-bit Linux | |
| Network | A public IPv4 address — IPv6 isn’t supported | |
How to set up an Arma Reforger dedicated server
Step 1: Download the server tool
Install SteamCMD, then download the server. It logs in anonymously; nobody needs to own Reforger on the server machine.
steamcmd +force_install_dir C:\reforger +login anonymous +app_update 1874900 validate +quitOn Linux, use a Linux path such as /home/reforger/server. The same line updates the server after a patch. You get ArmaReforgerServer.exe on Windows and ArmaReforgerServer on Linux. The experimental branch is a different app, 1890870, if you want to test upcoming builds.
Step 2: Create config.json
Create the file next to the executable. This is a minimal working config for Conflict on Everon:
{
"bindAddress": "0.0.0.0",
"bindPort": 2001,
"publicAddress": "203.0.113.25",
"publicPort": 2001,
"a2s": { "address": "0.0.0.0", "port": 17777 },
"game": {
"name": "My Reforger Server",
"password": "",
"passwordAdmin": "something-long-and-private",
"admins": [],
"scenarioId": "{ECC61978EDCC2B5A}Missions/23_Campaign.conf",
"maxPlayers": 64,
"visible": true,
"crossPlatform": false,
"gameProperties": {
"serverMaxViewDistance": 2500,
"networkViewDistance": 1500,
"disableThirdPerson": false,
"fastValidation": true,
"battlEye": true
},
"mods": []
}
}Put your real public IP in publicAddress. Keys are case-sensitive, and JSON is strict: one missing comma or an extra one after the last item and the server exits without a clear error. Paste the file into any JSON validator before you start the server if it won’t come up.
Step 3: Start it
On Windows, a one-line start.bat:
ArmaReforgerServer.exe -config .\config.json -profile .\profile -maxFPS 60On Linux:
./ArmaReforgerServer -config ./config.json -profile ./profile -maxFPS 60-profile is where logs and saves go. On the first start, the server registers with Bohemia’s backend and downloads any mods in the config, so give it a minute.
Step 4: Pick the scenario
The scenario is set by ID in scenarioId, not from a menu. Start the server once with -listScenarios added and it prints every ID it can load, including scenarios that come with your mods. Two you’ll see often:
| Scenario | scenarioId |
|---|---|
| Conflict, Everon | {ECC61978EDCC2B5A}Missions/23_Campaign.conf |
| Capture & Hold, Briars Coast | {3F2E005F43DBD2F8}Missions/CAH_Briars_Coast.conf |
The base game’s multiplayer modes are Conflict, Game Master, Combat Ops and Capture & Hold; each has its own IDs per map.
Linux and Docker
The Linux server is 64-bit only. LinuxGSM supports it if you want install, update, backup and monitor commands in one script. For Docker, the ACE team’s image maps UDP 2001, builds config.json from environment variables or uses your own file, and updates the server on every restart.
docker create --name=reforger-server -p 2001:2001/udp \
-v ./configs:/reforger/Configs -v ./profiles:/home/profile -v ./workshop:/reforger/workshop \
-e SERVER_PUBLIC_ADDRESS="your public ip" -e GAME_NAME="My Reforger Server" \
ghcr.io/acemod/arma-reforger:latestArma Reforger server config reference
The config has four parts: network settings at the top, game for what players see, gameProperties inside it for gameplay rules, and an optional operating block for server behaviour. These are the keys you’ll actually change.
| Key | What it does |
|---|---|
publicAddress / publicPort |
The IP and port the server registers with the backend. Wrong values = “server unreachable” |
game.name |
Name in the server browser (up to 100 characters) |
game.password |
Join password — set it to make a private server |
game.passwordAdmin |
Admin password for #login, no spaces |
game.admins |
Identity IDs or Steam IDs that can #login without the password |
game.maxPlayers |
How many players: 1 to 128 |
game.visible |
false hides the server from the browser |
game.crossPlatform |
true accepts all platforms |
game.supportedPlatforms |
Used when crossPlatform is false: PLATFORM_PC, PLATFORM_XBL, PLATFORM_PSN |
game.mods |
Workshop mods by ID (see below) |
gameProperties.disableThirdPerson |
First person only |
gameProperties.serverMaxViewDistance / networkViewDistance |
Lower these first when server FPS is low |
gameProperties.VONCanTransmitCrossFaction |
Lets radio reach the other faction |
gameProperties.battlEye |
Anti-cheat, on by default |
operating.aiLimit |
Caps AI characters; -1 is no limit |
operating.joinQueue.maxSize |
Queue length when full, 0 (off) to 50 |
operating.slotReservationTimeout |
Seconds a kicked player’s slot is held for them |
How to add mods to an Arma Reforger server
Reforger mods come from its own Workshop (in game, or at reforger.armaplatform.com/workshop), not the Steam Workshop. Each mod has a 16-character ID. List the IDs in game.mods; the server downloads them on start and players download them automatically when they join, so nobody installs anything by hand.
- Find the mod ID. It’s in the mod’s Workshop page address, e.g.
reforger.armaplatform.com/workshop/5AAAC70D754245DD-.... If you’ve already downloaded the mod in your game, itsServerData.jsoninDocuments\My Games\ArmaReforger\addons\(the Reforger mod folder) holds the ID, name and version too. - Add it to the config:
"mods": [ { "modId": "5965550F24A0C152", "name": "Where Am I" }, { "modId": "5AAAC70D754245DD", "name": "Server Admin Tools", "version": "1.7.1" } ]nameis just a label. Leave outversionto always run the latest; set it to pin one. Add"required": falseif the server should start even when that mod fails to download. - Restart the server. If a mod’s scenario doesn’t show up, run
-listScenariosagain and copy its new ID intoscenarioId.
That’s also how you join modded servers as a player: pick the server in the browser and the game downloads the mod list for you. Community servers built this way take the game well beyond its Cold War setting — zombie and DayZ-style survival, RP and life servers, Vietnam and WW2 conversions, Star Wars and Warhammer 40k, wasteland, modern warfare and Battlefield-style large battles. Admin mods add menus and logs on top of the chat commands, for example “Server Admin Tools” by ceo_of_bacon (the “bacon” admin tools).
Mods on Xbox and PS5
PlayStation players got Workshop access in Update 1.4 (May 2025), with 25 GB set aside for downloads. Whether a specific mod works on console is down to that mod, so test with a console friend before you build an event around it.
Crossplay: letting Xbox and PS5 players join
Which platforms can connect is a game setting in config.json. Set "crossPlatform": true to accept PC, Xbox and PS5. To pick, leave it false and list platforms in supportedPlatforms, for example ["PLATFORM_PC", "PLATFORM_XBL"] for PC and Xbox only. supportedPlatforms is ignored when crossPlatform is true.
“How do I create a server on Arma Reforger Xbox?” and “how to make a private server on PS5?” have the same answer: consoles can’t run the dedicated server, so someone runs it on a PC or rents one, turns on the right platforms and sets a game.password. Console players then find it by name in the server browser and enter the password.
Arma Reforger server ports
| Port | Protocol | What it’s for |
|---|---|---|
| 2001 | UDP | Game port — the one players connect to |
| 17777 | UDP | A2S (Steam query), only if the a2s block is set |
| 19999 | UDP | RCON, only if the rcon block is set |
For a home server, forward UDP 2001 (and 17777 if you use A2S) to the server PC and allow it through the firewall. Then set publicAddress to your public IP: behind a router the server can’t always work that out by itself, and a private address there makes the server show up but stay unreachable.
Admin, server commands and RCON
Set passwordAdmin, join, open chat and type #login yourpassword. Anyone listed in game.admins skips the password (up to 20 IDs).
| Command | What it does |
|---|---|
#login password |
Become admin |
#players |
List connected players and their IDs |
#kick id |
Kick a player (they can rejoin) |
#ban create id seconds reason |
Ban for a set time, e.g. #ban create 19874 3600 griefing |
#ban list / #ban remove id |
Show bans / lift one |
For remote admin tools, add an rcon block with an address, port 19999, a password of at least 3 characters with no spaces, and permission set to admin (full control) or monitor (read-only). A whitelist or blacklist limits which commands RCON clients may run.
Common Arma Reforger server issues and fixes
| Problem | Most likely cause | Fix |
|---|---|---|
| “Server unreachable” / replication server unreachable | Wrong publicAddress or publicPort, or UDP 2001 blocked |
Set your real public IP and port; forward UDP 2001; check the firewall |
Kicked with group=1 "REPLICATION", reason=3 "CONNECTION_FAILURE" |
The connection to the server dropped or never completed | Same checks as unreachable; then check the host’s upload and packet loss |
| “The response from the server took too long” | Server still starting or downloading mods, or the port is blocked | Wait for the first start to finish; check the log and the port |
| Server not showing up in the browser | visible is false, the server exited, or it never registered |
Set visible to true; read the console log; check the JSON |
| Server crashing or keeps restarting right after start | Broken JSON, wrong scenarioId, or a mod that fails to load |
Validate the JSON; get IDs from -listScenarios; remove mods one at a time |
| “Game resources don’t match server resources” | A player’s mod version differs from the server’s | Update or unpin the version; delete the mod’s folder on the server so it downloads again |
| Kicked because the server is full | maxPlayers reached |
Raise maxPlayers (up to 128) or turn on a join queue |
| Low server FPS | Too much AI or view distance for the CPU | Lower serverMaxViewDistance, set aiLimit, keep -maxFPS sensible |
| Crashing when joining a modded server | A broken mod download on the client | Delete that mod in the game’s Workshop menu and rejoin |
| Console players not connecting, or can’t connect to a friend’s server | The server doesn’t allow that platform | Turn on crossPlatform or add the platform to supportedPlatforms |
Is it just me, or are the servers down today? Every server registers with Bohemia’s backend to appear in the browser. If every community server disappears at once, it’s on their side and passes when the backend is back; operating.disableServerShutdown stops your server shutting itself down while the backend connection is lost.
How many players can join?
Up to 128 per server, set with game.maxPlayers. How many you can actually run smoothly depends on the scenario and the AI: a 128-player Conflict server needs much more CPU and RAM than a 10-player Game Master night.
Keeping the server updated
After a game update, stop the server and run the same SteamCMD line (app_update 1874900 validate), then start it again — mods without a pinned version update themselves on start. Back up the profile folder and config.json first; the profile holds saves and logs.
Skip the setup: rent an Arma Reforger server
Running Reforger yourself means a PC that stays on, a forwarded port, the right public IP in the config and a JSON file that quits without a word when one comma is missing. If you’d rather play, Arma Reforger server hosting on GameTeam is up in minutes: you pay per GB of RAM (from $0.49/GB a week) with unlimited slots, so a 128-player lobby costs the same as eight friends, and the built-in AI copilot writes the config for you. Tell it “add mod 5965550F24A0C152 and switch to Capture & Hold on Briars Coast” and it edits config.json, checks the JSON and restarts, or ask “the server starts and then just stops, why?” and it reads the log and points at the broken line. Server start, stop and restart events can go straight to your unit’s Discord with the Live Discord Bridge. Still running Arma 3 as well? The Arma 3 dedicated server guide covers its server.cfg setup.
FAQ
How do I host an Arma Reforger server for friends?
For a quick game, host a player-hosted session from the client. For a server that’s always up, install the dedicated server tool (app 1874900) with SteamCMD, write a config.json, forward UDP 2001 and start it with -config. Set a game.password to keep it private.
How much does it cost to host an Arma Reforger server?
The server tool is free. Self-hosting costs the PC and its electricity. Hosted servers are usually priced by slots or RAM; on GameTeam a 6 GB server is $2.94 a week with unlimited slots.
Where is the Arma Reforger mod folder?
On a PC client, downloaded mods are in Documents\My Games\ArmaReforger\addons\. On a dedicated server they download into the server’s own addons folder; delete a mod’s folder there to force a fresh download.
Can I add a mod manually instead of by ID?
Use the ID in game.mods: that’s how the server fetches the mod and how players download it automatically on join.
Can you play the Arma Reforger campaign with friends?
Operation Omega, the five-mission campaign, is single-player. Together you play the multiplayer modes: Conflict, Combat Ops, Capture & Hold, or Game Master, where one player builds the mission for the others.
How do I make someone admin?
Add their identity ID or Steam ID to game.admins, or give them the passwordAdmin to use with #login. Use #players in game to see IDs.
Is Arma 3 still alive in 2026, or should we play Reforger?
Both are still played. Arma 3 has thirteen years of missions, mods and milsim units behind it; Reforger runs on the newer engine, has console players, and its whole server setup is one JSON file. Plenty of groups run both — the Arma 3 guide covers the other one.
What are the best Arma Reforger servers?
The best server is the one with the mode and mods your group wants, a low ping and enough admins online. Search the in-game browser by mode, or run your own with exactly the rules you want.