Left 4 Dead 2 Server Admin, RCON & Director Commands: Console Reference

Left 4 Dead 2 dedicated servers use the standard Valve Source RCON protocol - the same one Counter-Strike and Team Fortress 2 use - so any Source RCON client works. But L4D2 layers its own quirks on top: lobby reservation that fights your cvars, an AI Director behind sv_cheats, and ban persistence rules that most guides get wrong. This reference covers the confirmed behavior.

Enabling RCON

RCON rides the game port (default 27015, TCP) - there is no separate RCON port. Enable it by setting a password in left4dead2/cfg/server.cfg:

rcon_password "your_strong_password"

Then from a client console: rcon_address <ip>:27015, rcon_password <password>, and prefix commands with rcon (e.g. rcon status). Dedicated RCON tools skip the prefix.

Game modes & mutations

The active mode is a single cvar:

mp_gamemode versus

Valid values: coop, realism, survival, versus, teamversus, scavenge, teamscavenge, and mutation IDs (mutation1 ... mutation20, community1 ... community6). Two related settings trip people up:

• sv_gametypes is a comma-separated whitelist of which modes lobby matchmaking may place on your server. If versus is not in sv_gametypes, lobbies will never send you a versus game - a classic "my server only runs coop" cause.
• Mutations can also be loaded directly with the map command: map c1m1_hotel mutation12 starts Realism Versus on Dead Center.

Changing maps: changelevel vs map

Map codes follow the c<campaign>m<chapter>_<name> pattern - c1m1_hotel (Dead Center), c2m1_highway (Dark Carnival), c5m1_waterfront (The Parish), c8m1_apartment (No Mercy). Run maps c in the console to list every installed campaign map rather than trusting a copied list - custom campaigns appear there too.

Player management

Run status first: it prints each player's name, userid, and Steam ID - the identifiers the moderation commands take.

Difficulty

z_difficulty Impossible

Values: Easy, Normal, Hard, Impossible (Expert). Settable live over RCON, applies to coop, realism, and survival. In versus the difficulty is hardcoded to Normal - z_difficulty has no effect there, and changing it requires a SourceMod plugin. Versus team-switching is limited by vs_max_team_switches (default 1).

The AI Director and sv_cheats

Most Director and horde-tuning commands are cheat-flagged: director_stop, director_start, director_panic_forever, director_force_panic_event, director_no_survivor_bots, z_common_limit, z_mob_spawn_max. They require sv_cheats 1, which applies server-wide and lets every connected client use cheat commands too - not a live-public-server setting.

One useful non-cheat distinction for filling seats: sb_add (spawn an extra survivor bot) is not cheat-flagged, while sb_takecontrol (possess a bot) is.

Direct connections & Steam group servers

Fresh L4D2 servers only accept lobby matchmaking traffic. To let players connect <ip> directly:

sv_allow_lobby_connect_only 0

To bind the server to your Steam group (members see it in the main menu's server list):

sv_steamgroup <group id>
sv_steamgroup_exclusive 1

sv_steamgroup_exclusive has three levels, not two: 0 = public; 1 = a group member must be in the game before the public can fill it; 2 = fully excluded from matchmaking. Known engine bug: very large (newer) group IDs above ~16.7 million fail to register - an old datatype limit.

More than 8 players

There is no supported vanilla cvar for raising the 4-player coop / 8-player versus caps. Larger servers use the l4dtoolz plugin (a MetaMod:Source plugin) to unlock real slots, typically alongside a SourceMod bot/spawn plugin so extra joiners get a survivor instead of sitting in spectator. sv_visiblemaxplayers only changes the advertised count in the browser, not the real cap.

SourceMod essentials

Serious L4D2 communities run MetaMod:Source + SourceMod. Admins are declared in addons/sourcemod/configs/admins_simple.ini; admin actions work from the server console, RCON, or in-game chat (!kick / /kick):

server.cfg essentials

hostname "My L4D2 Server"
rcon_password "your_strong_password"
sv_password ""            // set to require a join password
motd_enable 1             // shows left4dead2/motd.txt on join
sv_region 3               // 0 US-East, 1 US-West, 2 S.America, 3 Europe,
                          // 4 Asia, 5 Australia, 6 Middle East, 7 Africa, 255 World
sv_tags "hidden:0"        // browser tags; also the modern home of the old
                          // sv_search_key convention (use a "key:xxx" tag)
exec banned_user.cfg      // BEFORE any writeid - see ban persistence above
exec banned_ip.cfg

server.cfg is re-executed on every map load (it is the servercfgfile default), so live cvar experiments get reset at the next transition unless you write them into the file.

Common mistakes

• Assuming timed bans survive a restart. They never do - only permanent (banid 0 + writeid) bans persist.
• writeid before exec banned_user.cfg in server.cfg - wipes the existing ban file.
• Flipping sv_cheats 1 over RCON on a lobby-reserved server and concluding Director commands are broken - the reservation reverted it; unreserve first.
• Setting z_difficulty for versus - versus is hardcoded to Normal; only coop/realism/survival respect it.
• Using map on a live server for a simple rotation - it drops everyone; changelevel keeps them connected.
• Editing mp_gamemode but not sv_gametypes - direct connects get the new mode, but lobbies still only send whitelisted modes.

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Because Left 4 Dead 2 speaks genuine Valve Source RCON, MantaScope's web RCON connects to your server straight from the browser - send these commands, watch the live player list, and manage bans without a desktop tool - alongside population history, uptime tracking, scheduled restarts, and Discord alerts.