Holdfast Server Ports and Firewall

Holdfast dedicated servers use UDP ports for game traffic and Steam server browser queries. Understanding these ports is essential for self-hosted servers and helpful for troubleshooting connection issues on any host.

This guide is based on the official Holdfast server hosting documentation.

Default Ports

Setting	Purpose	Default
server_port	Game traffic (UDP)	20100
steam_query_port	Steam server browser queries, player count, map, etc. (UDP)	27000

Both ports must be unique for each server instance if you run multiple Holdfast servers on the same machine.

Example config:

server_port 20100
steam_query_port 27000

AleForge Hosted Servers

AleForge handles network configuration, port assignment, and firewall rules for your Holdfast server. You do not need to configure port forwarding or open ports manually.

To find your assigned ports:

1. Open the Blacksmith’s Portal
2. Select your Holdfast server
3. Check the sidebar for your IP and game port
4. Review your config file in holdfastnaw-dedicated/configs for server_port and steam_query_port values

If your server isn’t appearing in the browser, verify the server has fully started in Console and that your steam_query_port is set correctly in your config.

Self-Hosted: Port Forwarding and Firewall

To allow players outside your local network to connect, you must:

1. Open UDP ports server_port and steam_query_port in your local firewall
2. Configure port forwarding on your router for both UDP ports to your server machine’s local IP

Without port forwarding, only players on your local network can connect (using Localhost via Join Custom Server).

Windows Firewall

1. Open Windows Defender Firewall → Advanced Settings
2. Create inbound rules allowing UDP traffic on your server_port and steam_query_port

Router Port Forwarding

1. Log in to your router’s admin panel
2. Forward UDP 20100 (or your custom server_port) to your server’s local IP
3. Forward UDP 27000 (or your custom steam_query_port) to the same IP
4. Restart your Holdfast server and test from an external connection

Running Multiple Server Instances

Each instance needs unique ports. For example:

Instance	server_port	steam_query_port
Server 1	20100	27000
Server 2	20101	27001

Update both the config file and any Docker environment variables (SERVER_PORT, STEAM_QUERY_PORT) if using the official Docker image.

Troubleshooting

• Server not in browser: Verify steam_query_port is open and forwarded. This port is what the server browser uses to display player count and map info.
• Can’t connect but server shows in browser: Check server_port firewall and forwarding rules.
• Works locally but not externally: Port forwarding is not configured correctly on your router.

AleForge customers don’t need to manage ports manually. Self-hosters should follow the Holdfast wiki and ensure both UDP ports are open and forwarded.