# How to Install a Garry's Mod Server

Install a Garry's Mod dedicated server: SRCDS download, port 27015, workshop addons & server.cfg – complete setup guide.

**Quick answer:** Install GMod server via SteamCMD (app 4020), open port 27015 UDP, configure server.cfg and add workshop addons.

This guide shows you step by step how to set up a Garry's Mod (GMod) Dedicated Server – both on Windows and Linux. GMod thrives on mods and custom content, so we also cover setting up addons directly.

## Requirements

    - **Operating system:** Windows 10/11 (64-bit) or Linux (Debian/Ubuntu)
- **Processor:** Relatively undemanding – a modern dual-core is sufficient for small servers. CPU load depends heavily on installed addons
- **RAM:** 2-4 GB for small servers with 16 slots, 4-6 GB for 32 slots, 6 GB+ for 64 slots with many addons
- **Storage:** 10 GB free disk space, more depending on the number of addons and maps
- **Network:** UDP port 27015 must be open. Sufficient upload bandwidth – about 0.5-1 Mbps per player
- **SteamCMD:** For downloading server files (free, no Steam account required)

## Step 1: Download and Set Up SteamCMD

SteamCMD is Valve's command-line tool for downloading server files. You don't need a Steam account – login is anonymous.

### Windows

    - Download SteamCMD from the official Valve website
- Create a folder, e.g. `C:\steamcmd`
- Extract the ZIP file into this folder
- You should now see `steamcmd.exe` in the folder

### Linux (Debian/Ubuntu)

`# Install dependencies
sudo apt install -y lib32gcc-s1 lib32stdc++6 curl tar

# Create SteamCMD folder
mkdir ~/steamcmd && cd ~/steamcmd

# Download and extract SteamCMD
curl -sqL "https://steamcdn-a.akamaihd.net/client/installer/steamcmd_linux.tar.gz" | tar zxvf -

# Start and update SteamCMD
./steamcmd.sh`

## Step 2: Download Garry's Mod Server Files

Start SteamCMD and run the following commands. The App ID for the Garry's Mod Dedicated Server is **4020**:

`# Set installation directory
force_install_dir C:\gmod-server    # Windows
force_install_dir ~/gmod            # Linux

# Anonymous login (no Steam account needed)
login anonymous

# Download server files
app_update 4020 validate

# Quit SteamCMD
quit`
The download takes a few minutes. Using `validate` checks files for corruption – it's slower but safer.

## Step 3: Create Server Startup Script

### Windows (start-server.bat)

Create a new text file `start-server.bat` in the server folder with the following content:

`@echo off
.\srcds.exe -game garrysmod -console -ip 0.0.0.0 -port 27015 +maxplayers 32 +map gm_construct`

### Linux (start-server.sh)

`nano ~/gmod/start-server.sh`
Add the following content:

`#!/bin/bash
./srcds_run -game garrysmod -console -ip 0.0.0.0 -port 27015 +maxplayers 32 +map gm_construct`
Make the file executable:

`chmod +x ~/gmod/start-server.sh`

**Explanation of startup parameters:**

    - **-game garrysmod:** Starts the game as Garry's Mod
- **-console:** Displays the server console
- **-ip 0.0.0.0:** Binds the server to all network interfaces
- **-port 27015:** Default port for GMod (UDP)
- **+maxplayers:** Maximum number of players (default: 32)
- **+map:** Starting map – `gm_construct` or `gm_flatgrass` are good defaults

## Step 4: Open Firewall Ports

Garry's Mod uses **UDP port 27015** for game connection and **UDP 27005** for the client.

### Linux (UFW)

`sudo ufw allow 27015/udp
sudo ufw allow 27005/udp`

### Windows Firewall (PowerShell as Administrator)

`New-NetFirewallRule -DisplayName "GMod Server" -Direction Inbound -Protocol UDP -LocalPort 27015,27005 -Action Allow`

Then forward the ports in your router to your server's local IP address.

## Step 5: Start Server and First Test

    - **Windows:** Double-click `start-server.bat`
- **Linux:** `./start-server.sh`
- The console shows the startup process – wait until `VAC secure mode is activated` appears
- The server is now ready for connections

## Step 6: Server Configuration (server.cfg)

You'll find **server.cfg** in the `garrysmod/cfg/` folder. Create or edit it:

`// Server name
hostname "My GMod Server"

// Password (leave empty for public server)
sv_password ""

// RCON password for remote control
rcon_password "your-secure-password"

// Region (255 = Worldwide)
sv_region 255

// Allow download of server-side files
sv_allowdownload 1
sv_allowupload 1

// Language
sv_lan 0

// Maximum tickrate
sv_minrate 50000
sv_maxrate 128000`

## Step 7: Install Addons from Steam Workshop

The easiest method to install mods is a **Steam Workshop Collection**. The server downloads the addons automatically and players receive them when connecting.

### Create and Link a Collection

    - Create a collection in the Steam Workshop
- Add the desired addons
- Copy the collection ID from the URL (e.g. `382793424`)
- Create a Steam Web API Key at [steamcommunity.com/dev/apikey](https://steamcommunity.com/dev/apikey)
- Add the following parameters to your startup script:
        `+host_workshop_collection 382793424 -authkey YOUR_API_KEY`
    

### Manual Addon Installation

For individual addons without a Workshop Collection:

    - Download the addon (usually a folder with `lua/`, `models/` etc.)
- Copy the folder to `garrysmod/addons/`
- Restart the server

## Step 8: Change Gamemode

GMod offers countless gamemodes – from Sandbox to TTT to DarkRP. Set the gamemode in the startup script:

`# Sandbox (Default)
+gamemode sandbox

# Trouble in Terrorist Town (TTT)
+gamemode terrortown

# Prop Hunt
+gamemode prop_hunt

# DarkRP
+gamemode darkrp

# Zombie Survival
+gamemode zombiesurvival`

## Step 9: Join the Server

    - Launch Garry's Mod on your PC
- Open the console with the **~** key (enable it in settings first)
- Enter: `connect your-server-ip:27015`
- Alternatively: Add the server to Steam favorites and join via the legacy browser

## Step 10: Make Yourself Admin

    - Find your SteamID (e.g. on [steamid.io](https://steamid.io))
- Open `garrysmod/settings/users.txt` (create if it doesn't exist)
- Add:
        `"admins"
{
    "STEAM_0:1:12345678"
    {
        "name"  "YourName"
        "group"  "superadmin"
    }
}`
    
- Restart server or use `ulx adduser YOURNAME superadmin` in the console (if ULX is installed)

## Hardware Recommendations by Server Type

    
        Server Type
        RAM
        CPU
        Slots
    

    
        Sandbox / Light
        2-4 GB
        2 cores
        16
    

    
        TTT / Prop Hunt
        4-6 GB
        2-3 cores
        32
    

    
        DarkRP with Addons
        6-8 GB
        3-4 cores
        64
    

    
        Many Addons (100+)
        8-12 GB
        4 cores at 3.5 GHz+
        64+
    

## Common Problems

**Server not showing in the server list:**

    - Check if UDP port 27015 is open in firewall and router
- Make sure `sv_lan 0` is set in server.cfg

**Players cannot download addons:**

    - Use a Workshop Collection – this is the most reliable method
- Check if the Steam Web API Key is valid
- Make sure `sv_allowdownload 1` is set

**Server crashes on startup:**

    - Check if all required libraries are installed (Linux: `lib32gcc-s1 lib32stdc++6`)
- Faulty addons can prevent startup – temporarily remove all addons for testing

**High CPU load:**

    - Reduce tickrate in server.cfg: `sv_minrate 20000`
- Limit the maximum number of players
- Remove resource-intensive addons

## Quick Checklist

    - SteamCMD installed and started
- Server files downloaded with `app_update 4020 validate`
- Startup script created (.bat or .sh)
- Firewall ports 27015 and 27005 opened
- server.cfg adjusted (hostname, password, RCON)
- Server started and console checked for errors
- Optional: Workshop Collection linked
- Joined with `connect ip:27015`
- Added yourself as admin