How to Host a KF2 Server at Home - Common Issues and Fixes

Killing Floor 2 runs well on dedicated servers, but finding one close to you with your friends can be hard. This page, based on a popular Steam guide, shows how to host your own from a home PC and, most usefully, how to fix the usual problems: a server that never reaches Steam, does not show in the browser or works only on LAN.

Cover image of the original Steam guide.

Start with port forwarding

Open these ports on your modem or router and point them at the server PC:

Port	Protocol
7777	UDP
27015	UDP
8080	TCP
20560	UDP

The author simply opened all four for both UDP and TCP. On a 30 Mbit download / 3 Mbit upload home line, local players saw about 60-70 ms ping and international players about 120-140 ms. Upload speed is the number that matters for hosting.

Use the server PC's local IPv4 address (from ipconfig) as the forwarding target, and ideally make that address static so the rule does not break after a reboot. The address shown by "what is my IP" websites is your public IP: that is what friends connect to, not what you forward to. Also allow the ports in the Windows firewall. More background: server ports and NAT.

Install with SteamCMD

You only need SteamCMD to download the server once and then to update it whenever KF2 gets a patch.

1. Put steamcmd.exe in its own folder (not loose on the desktop: it unpacks dozens of files next to itself) and run it. It updates itself; exit when done.
2. Run it again and log in:

login anonymous

3. Optional - choose where the server goes:

force_install_dir c:\KF2Server\

4. Download the server:

app_update 232130

To update later, repeat force_install_dir (if you used it) and run:

app_update 232130 validate

SteamCMD checks the files and downloads the patch.

First launch and config

1. Run KF2Server.bat once so the default config files are created. A desktop shortcut is handy.
2. Close the server window before editing files.
3. Open KFGame\Config\PCServer-KFGame.ini. You only need to edit it by hand if you cannot use WebAdmin, which is the easier option.

Line	What it does
GameDifficulty	0 = Normal, 1 = Hard, 2 = Suicidal, 3 = Hell on Earth
ServerName	Name shown in the server browser
GamePassword	Password players need to join
GameLength	0 = 4 waves, 1 = 7 waves, 2 = 10 waves

WebAdmin

1. Run ipconfig in Command Prompt and copy your IPv4 address.
2. In a browser open it with :8080 on the end, for example http://192.168.25.22:8080/.
3. Default login: admin / 123. Change the password.

Common issues

The STEAM GAME SERVER UID line does not appear

This line is your server's ID on Steam and appears every time the server is running and reporting to Steam. If it is missing:

• close the game before starting the server
• open the ports listed above
• add an exception for the KF2 server in your firewall and antivirus

The server does not show in the server browser

Usually the port forwarding is wrong or incomplete. As a last resort the guide suggests DMZ:

1. Find the server PC's local IPv4 with ipconfig.
2. Enter that address as the DMZ host in the router.
3. Save and restart the modem.

DMZ exposes the whole PC to the internet, so treat it as a test, not a permanent setup. Go back to normal port forwarding once you know what was wrong.

The server works only on LAN

Players on your network can join, but friends cannot. That means the ports are not reaching the server: forward them on the router (not only in Windows), check the firewall, and if the router is behind another NAT device or your ISP blocks forwarding, contact the ISP.

WebAdmin will not open

Enable it: open KFWeb.ini, find the [IpDrv.WebServer] section and set bEnabled=true.

SteamCMD will not download the server

• try another disk or folder
• run SteamCMD as administrator
• if you see "Failed to request AppInfo update, not online or not logged in to Steam", you forgot login anonymous before app_update

If everything looks right and it still fails, check that no firewall or antivirus is blocking the server.

Recommended tools and mutators

• KF2ServerTool - install and configure the server, add and update Workshop maps and mods, run updates and integrity checks, start with custom mutators, and keep several profiles. See KF2ServerTool overview.
• Magicked Administrator - a chat bot for KF2 servers that tracks player stats and accepts server commands through in-game chat.
• Classic Scoreboard - replaces the stock scoreboard and shows each player's cash, exact perk level and exact health.
• Server Extension (RPG mod) - replaces the standard perk system with server-side progression where players buy individual stats and traits.

Daily use

Every time you want to host, run KF2Server.bat and keep its window open while people play: closing it shuts the server down. Update the server through SteamCMD every time the game gets a patch, or clients will not be able to join.