L4D2 Dedicated Server: Setup, Joining Without a Lobby and Modes

An L4D2 dedicated server keeps your campaign off any player's PC, so nobody hosts on a weak upload and the run survives the host leaving. This guide covers Valve's Left 4 Dead 2 dedicated server, running it on our Left 4 Dead 2 server hosting, how to join without a lobby, the game modes and how to moderate.

• What it is: Valve's free Left 4 Dead 2 Dedicated Server, Steam app 222860.
• Joining: players connect by address from the developer console. We switch off lobby-only connections for you.
• Players: 2 to 8. Four for a co-op campaign, eight for Versus.
• On 1up: the server needs 1 GB of RAM. It runs on Free at ×1, so the hourglass does not speed up, and 24/7 from Casual.

1. Self-host or hosting?

Left 4 Dead 2 normally sends your group through a lobby, which picks a Valve server or lets one player host. A dedicated server of your own fixes the address, the rules and the ping.

• Self-host: install the server with SteamCMD (app 222860), start it with -game left4dead2 and a map, and open UDP 27015 on your router. Add sv_allow_lobby_connect_only 0 to its server.cfg, or nobody will reach it by address.
• A hosted server: the server runs in a data centre and you manage it from a web panel.

2. Create an L4D2 server on 1up

1. Create an account and press Create server.
2. Choose Left 4 Dead 2. It fits every plan, Free included: there your free time runs at the normal pace, with no hourglass multiplier. For a server that stays online 24/7, pick Casual or above.
3. Pick a region, London or Paris. The wizard measures your ping and suggests the nearest one.
4. Set the slots and the opening chapter. Optionally paste a Steam GSLT for app ID 550.
5. Create the server. The very first start downloads the game twice (Windows files, then the Linux ones) and takes longer than any later boot.
6. When it is online, the Overview shows the IP line with the address and port.

3. The panel settings

The Game tab sets five things; the panel shows a preview of the launch line and the server.cfg it writes.

The token is optional: the server runs and accepts players by address without one. If you want one, create it on Steam's game server account page with app ID 550. Your account must own the game and have a registered phone, and each server needs its own token.

The starting map is a map code. Each campaign is c<number>m<chapter>, as Valve's list of L4D2 missions files shows. Some first chapters:

When the survivors reach the safe room, the server moves to the next chapter by itself.

4. Modes and your own cvars

The server starts in co-op. Versus, Survival, Scavenge and Realism come from mp_gamemode, which you set in your own config file.

We rewrite left4dead2/cfg/server.cfg at every start, so edits there are lost. Your lines go in left4dead2/cfg/1up-owner.cfg, a file we create empty once and never overwrite. Open it in the Files tab:

mp_gamemode versus

Restart, and load a map made for that mode. Use 8 slots for Versus: four survivors against four special infected.

Unlike our other Source servers, Left 4 Dead 2 keeps its in-game votes. Every vote variable is locked behind cheats on this build, so we cannot switch them off for you.

5. How players connect

There is no lobby step. Each player:

1. Enables the developer console in the game's keyboard options.
2. Opens it and types connect with the address and port from the IP line, for example connect 203.0.113.10:31015.
3. Types the password if you set one.

Copy both numbers from the panel: our port is not 27015. If a friend gets a lobby error, they used the matchmaking menu instead of connect.

6. Moderating from the panel

The Console tab sends the server's own commands:

• say messages everyone, kick and kickid remove a player by name or by user ID with a reason.
• banid bans a Steam ID for a number of minutes (0 for good); removeid lifts it. Bans are written to disk and loaded on every start.
• changelevel jumps to another chapter or campaign; status lists who is connected.

The Players tab shows each connected Steam profile with hours played and any VAC record, and the console's activity view counts kills, deaths and chat.

7. When nobody can get in

• "Lobby" or "matchmaking" errors: the player used the game's lobby menu. Use connect with the address and the port.
• The first start looks frozen: it is the download. Watch the Console until the first map loads; it fetches the Windows files once, then the Linux ones.
• The server stops after you edit your cfg: a line in 1up-owner.cfg broke it. Empty the file, restart, and read the console for the command the engine rejected.
• Wrong password: a new password only applies after a restart.

8. Limits worth knowing

• No Workshop campaigns in the panel. Custom campaigns are not installed for you; the addons folder is kept across restarts if you add files yourself.
• Slots follow the plan. Casual has 6, so a full Versus game of 8 needs Starter (10) or above.

For the RAM, the server idles at about 250 MB, so 1 GB leaves plenty of margin and 2 GB suits a busy Versus server. Disk is the real constraint: the install is about 9.4 GB. With prices from our pricing page, Free (€0) gives 4 slots and no backups, enough for a four-player co-op campaign; Casual (€3/month) gives 2 GB of RAM, 20 GB of disk, 6 slots, 1 backup and 24/7 uptime; Starter (€5/month) gives 4 GB, 20 GB and 10 slots.

If your group also plays other classics, our guides to a TF2 dedicated server and a Garry's Mod dedicated server follow the same steps. For sandbox nights between campaigns, our Garry's Mod server hosting runs Facepunch's Source sandbox 24/7 from Casual.

Tested on Left 4 Dead 2 Dedicated Server build 23990100, 2026-10-08: settings, files and commands checked against our image on 1up v0.282.4; plans re-checked on 1up v1.9.2, 2026-10-20.

Change log

• 2026-10-25: plan figures updated from the live plans list.
• 2026-10-20: Left 4 Dead 2 is no longer in beta and runs on Free too (×1 on the hourglass); 24/7 from Casual at €3.
• 2026-10-08: first version.