How to host a Left 4 Dead 2 server: game modes, lobby settings and addons

Left 4 Dead 2 is still one of the best co-op games to play with friends, and a dedicated server makes it better: no host player whose connection drags everyone down, custom campaigns that stay installed, and rules you set yourself. The server is free from Valve, runs on the Source engine, and is controlled by a handful of console variables and a server.cfg. This guide explains how it works, the settings that cause most of the confusion (lobby joins and game modes), addons and SourceMod, and how we set one up for you on GGHOST Cloud.

How an L4D2 dedicated server works

An L4D2 server runs the full simulation: the survivors, the Director that decides when hordes and special infected spawn, every common infected on screen, and every shot. That makes it busier than its player count suggests. A four-player co-op game can have a lot happening at once during a panic event, and nearly all of it runs on the server’s main thread. A fast CPU core matters more than lots of cores.

Unlike some newer Valve titles, L4D2 does not need a Steam Game Server Login Token. You can start the server and have it reachable straight away.

What drives CPU and memory use

We do not publish a fixed sizing table for L4D2, because what you run on it changes the load a lot. The main factors are:

• Mode and player count. Standard co-op is four survivors; versus is two teams. More players means more of everything.
• Hordes. Panic events, finales and modified Director settings put the most strain on the server.
• Plugins. SourceMod is light on its own; large plugin sets that change spawns or add features add CPU time.
• Custom campaigns. Some are much heavier than the official ones.

Tell us the modes, campaigns and player count you have in mind, and we size the server with you. You pay for memory, not player slots.

Server config essentials

L4D2’s settings live in left4dead2/cfg/server.cfg. Edit it from the panel’s file manager or over SFTP, then restart.

Lobby connections

The setting that confuses most new server owners is sv_allow_lobby_connect_only. With it set to 1, players can only reach the server through the in-game matchmaking lobby. Set it to 0 to allow joining through the server browser, Steam invites and the connect command. For a private group server, you almost always want 0.

Game modes

Two variables control the mode:

• mp_gamemode: the mode the server is running now, such as coop, realism, versus, survival or scavenge.
• sv_gametypes: the modes the server allows or advertises, as a comma-separated list.

For a server dedicated to one mode, set both to match. Be aware that a lobby or a map change can switch mp_gamemode, so if you want to lock it down, restrict sv_gametypes as well.

Other useful settings

• hostname for the browser name.
• sv_password for a private server.
• rcon_password for remote admin.
• sv_steamgroup to tie the server to your Steam group, so members can find it.

Addons and custom campaigns

Custom campaigns, maps and many mods come as VPK files. On the server they go in left4dead2/addons. Players need the same content on their own game, which they usually get by subscribing to it on the Steam Workshop. If a player is missing a campaign the server is running, they will not be able to play it.

SourceMod and Metamod

L4D2 is fully supported by Metamod:Source and SourceMod. With them you get an admin menu, kick and ban tools, map voting, and a large library of community plugins, from small quality-of-life fixes to complete competitive configs for versus. Admins go in addons/sourcemod/configs/admins_simple.ini by SteamID.

Change one thing at a time. Gameplay plugins in L4D2 often touch the same Director and spawn logic, and two of them fighting each other is hard to diagnose if you installed five at once.

Performance and fair-play tips

• Pick the region closest to your group. L4D2 is very sensitive to ping, especially in versus. Our live regions today are Singapore and Europe (France–Germany border), with the United States (East, Central and West), the United Kingdom, India, Japan and Australia on demand.
• Restart on a schedule. A daily restart at a quiet hour keeps a long-running server fresh. Set it as a scheduled task in the panel.
• Be careful with “more zombies” plugins. Larger hordes are fun, but they are the fastest way to push the server past what it can simulate smoothly.
• Use a password or Steam group for private servers, so random lobby players are not dropped into your campaign night.
• Give moderators their own access. Use SourceMod admin entries and panel sub-users instead of sharing one login.

Installing addons and plugins safely

Upload VPKs to addons and SourceMod plugins to addons/sourcemod/plugins over SFTP or through the file manager, then restart and read the console for errors. Two habits help:

• Keep plugins current. Old plugins that depend on outdated game data are a common reason things break after a game update.
• Back up first. Take a backup from the panel before adding a large plugin set or replacing your configs.

Backups

On GGHOST Cloud, backups run on a schedule you set and restore from the panel without opening a ticket. Your configs, admin lists and plugin settings are the parts worth protecting; a daily backup plus a manual one before every change is plenty. If you are moving from another host, upload your cfg and addons folders over SFTP and carry on.

Getting an L4D2 server on GGHOST Cloud

Left 4 Dead 2 is set up on request rather than through instant checkout:

1. Tell us what you need. Ask us on Discord (or open a ticket) with the game mode, campaigns or mods and player count you need.
2. We size it and quote. We work out the headroom for that setup and quote a monthly price. No setup fee, no contract; billing runs through app.gghost.cloud.
3. We set it up on our Pterodactyl panel, usually within a few days.
4. Share the address. Start the server and give players the address and port shown in the panel.

You then have the full panel at panel.gghost.cloud: live console, file manager, SFTP, scheduled tasks, sub-users and database access. You can change startup flags from the panel and restart. Every node is behind DDoS protection from our network providers, and support comes from the people who run the servers, on Discord or at hello@gghost.cloud.

The short version

Set sv_allow_lobby_connect_only 0 so friends can join directly, match mp_gamemode and sv_gametypes for the mode you want, put custom campaigns in addons and make sure players have them too, and add SourceMod for admin tools. Change one plugin at a time, back up before changes, and ask us on Discord when you want a server set up.