Here's how to connect to your Arma 3 server and adjust the most important settings.

Connecting

Open the server page in the client area and click Start.
Wait until the status shows “running”. You can follow the progress in the Console tab.
Copy the address (IP:Port) at the top of the server page.
Find the server in the Arma 3 server browser or use direct connect there with this address.

Important settings

In the Startup variables tab:

Server password (SERVER_PASSWORD) – password for joining; leave empty for no protection.
Max. players (MAX_PLAYERS) – maximum number of players.
Mod list (MOD_FILE) – file name of a mod list exported from the Arma 3 Launcher (upload the HTML file in Files).
Additional mods (MODIFICATIONS) – semicolon-separated mod folders, e.g. manually uploaded mods.
Automatic updates (UPDATE_SERVER) – checks for server and mod updates on start.

The server name and other settings are in server.cfg in the Files tab. Changes in the Startup variables tab take effect on the next restart.

The most important entries in server.cfg

hostname = "My Server"; – name in the server list
passwordAdmin = "…"; – password for admin login in the game
motd[] = {"Welcome", "Rules: …"}; – welcome messages when joining
BattlEye = 1; – anti-cheat on
verifySignatures = 2; – only signed mods allowed

Stop the server before editing the file.

Admin in the game

Open the chat in the game and enter #login YourAdminPassword. Commands such as #missions (choose mission), #restart, #kick playername or #lock (lock the server) are then available.

Custom missions

Upload mission files (.pbo) to the mpmissions folder in the Files tab. After a restart, select them as admin with #missions.

How much memory?

The base configuration is enough to start. The more players play at the same time and the more mods and AI units run, the more memory the server needs. With large mod collections and many AI enemies, a headless client is also worthwhile (startup variable Headless clients).

Good to know

The first start takes longer because the server files are downloaded and set up.

Arma 3: connect to and set up your server