How to Host a Left 4 Dead 2 Server (2026 Guide)

Q: Why can my friends not connect from the console?

The server is set to lobby only. Add svallowlobbyconnectonly 0 to server.cfg and restart.

Q: Why does my Versus server keep starting co-op games?

Set svgametypes "versus" as well as mpgamemode versus. Otherwise lobbies can still start other modes on it.

To host a Left 4 Dead 2 server, download SRCDS with SteamCMD app 222860, create left4dead2/cfg/server.cfg with sv_allow_lobby_connect_only 0 and your sv_gametypes, then start it with -game left4dead2 +map c1m1_hotel. Open UDP and TCP 27015. Friends join with connect IP:27015 in the console, or by starting a lobby and forcing it onto your server with mm_dedicated_force_servers. A stock server runs on 2 GB.

What do you need to host an L4D2 server?

Left 4 Dead 2 runs on the Source engine, and its dedicated server is easy on hardware. It runs on Windows and Linux.

Server	RAM	Notes
Stock co-op or 4v4 Versus	2 GB	The base game
8 survivor co-op with plugins and a few custom campaigns	3 GB	The usual friends setup
Long plugin list and many large Workshop campaigns	4 GB	Big custom map libraries

The base game allows 4 players in co-op and 8 in Versus (4 survivors against 4 special infected). Community servers use SourceMod and slot plugins to run campaigns with more survivors. Everyone needs their own copy of L4D2 on Steam, and Left 4 Dead 1 players cannot join: they are separate games.

Survivors fighting a horde in a Left 4 Dead 2 campaign on a dedicated server

How do I install a Left 4 Dead 2 dedicated server?

Install SteamCMD and download the server anonymously:

steamcmd +force_install_dir C:\l4d2server +login anonymous +app_update 222860 validate +quit

Create left4dead2/cfg/server.cfg (next section).
Start the server. On Windows:

srcds.exe -console -game left4dead2 -port 27015 +map c1m1_hotel

On Linux:

./srcds_run -console -game left4dead2 -port 27015 +map c1m1_hotel

Forward UDP and TCP 27015 if you host at home (port forwarding guide).

c1m1_hotel is the first map of Dead Center. Each official campaign follows the same pattern, c2m1_highway for Dark Carnival, c8m1_apartment for No Mercy and so on. Run the SteamCMD line again after game updates.

How do I configure server.cfg?

A good starting point for a private co-op server:

hostname "Our L4D2 Server"
rcon_password "use-a-long-random-password"
sv_allow_lobby_connect_only 0
sv_gametypes "coop,realism,survival,versus,scavenge"
mp_gamemode coop
z_difficulty Normal
sv_region 255
sv_lan 0
sv_steamgroup 0
sv_steamgroup_exclusive 0

Setting	What it does	Good value
`sv_allow_lobby_connect_only`	`1` only lets players in through a lobby	`0`, so `connect` and Steam invites work
`sv_gametypes`	Which modes lobbies may start here	List every mode you want to allow
`mp_gamemode`	Mode the server starts in	`coop`, `realism`, `versus`, `survival` or `scavenge`
`z_difficulty`	Co-op difficulty	`Easy`, `Normal`, `Hard` or `Impossible`
`sv_steamgroup`	Your Steam group's ID	Lets the group's lobbies find the server
`sv_steamgroup_exclusive`	Restricts lobby use to the group	`1` to keep strangers' lobbies off it

server.cfg runs when a map loads. After editing, type exec server.cfg or change the map.

How do I move a lobby to my dedicated server?

L4D2 was built around lobbies, which by default pick a Valve or random server. You have two ways to land on yours:

Direct connect. Enable the developer console in Options > Keyboard/Mouse, press ~, and type connect 203.0.113.10:27015. This needs sv_allow_lobby_connect_only 0.
Force the lobby. The lobby leader opens the console before starting and runs mm_dedicated_force_servers 203.0.113.10:27015, then starts the lobby with Best Available Dedicated as the server type. The whole lobby is sent to your server.

A third option is a Steam group server: set sv_steamgroup to your group's ID, and members can pick the group's server when they create a lobby. Every cvar mentioned here is described in the Valve Developer Community's list of L4D2 console commands and variables.

How do I set up a Versus server?

Set both of these in server.cfg:

mp_gamemode versus
sv_gametypes "versus"

If you only change mp_gamemode, lobbies can still land on the server in co-op. Start on a Versus friendly map (the official campaigns all work) and restart. For league play, competitive configs such as the popular community config packs add ready up, fixed spawns and match rules on top of SourceMod.

Mutations work the same way: set mp_gamemode to the mutation's mode name and pick a map that supports it.

How do I run custom campaigns?

Custom campaigns are .vpk files in left4dead2/addons on the server.

Get the campaign's .vpk. For a Workshop campaign, subscribe in Steam, then copy the file from left4dead2/addons/workshop in your own game folder.
Upload it to left4dead2/addons on the server with SFTP.
Restart the server and change to the campaign's first map with changelevel <mapname>.
Post the Workshop link for your players. Everyone needs the same campaign installed or subscribed, or they cannot join that map.

Keep the version on the server and the Workshop version in sync. When an author updates a campaign, upload the new .vpk too.

How do I install SourceMod on L4D2?

Download the stable builds of Metamod:Source and SourceMod for your server's OS.
Extract both into the left4dead2 folder so you have left4dead2/addons/metamod and left4dead2/addons/sourcemod.
Restart and check with meta list and sm plugins list in the console.
Make yourself admin in left4dead2/addons/sourcemod/configs/admins_simple.ini:

"STEAM_1:1:12345678" "99:z"

Popular plugins add more survivor slots (L4DToolZ together with a survivor bot plugin for 8+ player co-op), admin menus, stats and special infected tweaks. Take a backup before adding a batch of plugins so a broken one is a quick restore: see how to back up a game server.

FAQ

How many players can join a Left 4 Dead 2 server?

The base game allows 4 in co-op and 8 in Versus. With Metamod, SourceMod and slot plugins like L4DToolZ, community servers run co-op with 8 or more survivors.

Why can my friends not connect from the console?

The server is set to lobby only. Add sv_allow_lobby_connect_only 0 to server.cfg and restart.

Why does my Versus server keep starting co-op games?

Set sv_gametypes "versus" as well as mp_gamemode versus. Otherwise lobbies can still start other modes on it.

Do players need custom campaigns to join?

Yes. If the server runs a custom campaign, every player needs the same campaign installed in addons or subscribed on the Workshop.

Does an L4D2 server need a lot of RAM?

No. A stock server sits comfortably on 2 GB, and 3 to 4 GB covers plugins and custom campaigns.

The easy option: host it with us

If you would rather skip SteamCMD and port forwarding, you can rent a Left 4 Dead 2 server from us. The panel covers the default map and auto updates, and server.cfg, the addons folder and your campaigns are in the file manager or over SFTP, with a live console for testing changes. It is ready minutes after you pay, with DDoS protection and backups before game updates. Plans start at 2 GB, new customers get 50% off the first month, and your survivor crew can split the bill. For more co-op ideas, see best zombie survival games with dedicated servers.