How to host a Call of Duty 1 dedicated server

Call of Duty 1 shipped in 2003 and its Linux dedicated server, cod_lnxded, is a 32-bit binary from November 2004. It still runs fine on a current distribution, but only once you have solved two problems the original readme never mentions: 32-bit runtime libraries, and the fact that the community is split between patch 1.1 and patch 1.5, which are not wire-compatible with each other.

This guide covers both.

What you need

The full 1.5 patch is on the war24.net download page, together with the CoD RCON tool.

1.1 or 1.5?

Pick before you build anything, because clients cannot cross-connect.

Mismatched clients are rejected with EXE_SERVER_IS_DIFFERENT_VER1.X. Most public servers today run 1.5; the 1.1 scene survives mainly around the AWE mod and CodExtended.

Directory layout

/opt/cod1/
├── cod_lnxded
└── main/
    ├── pak0.pk3 … pakb.pk3
    ├── localized_english_pak0.pk3 …
    ├── server.cfg
    └── zz_yourmod.pk3        # optional

Note the localized paks run localized_english_pak0, 1, 2, 3, 5 — there is no localized_english_pak4. That gap is normal, not a missing file.

32-bit libraries on a modern distro

cod_lnxded is i386. On a 64-bit Debian or Ubuntu:

sudo dpkg --add-architecture i386
sudo apt update
sudo apt install -y libc6:i386 libgcc-s1:i386 lib32stdc++6 libstdc++5:i386

libstdc++5 is the one people miss. Without it the binary dies immediately with error while loading shared libraries: libstdc++.so.5.

server.cfg

Put this in main/server.cfg:

seta sv_hostname "^3My ^7CoD1 Server"
set g_gametype "dm"
set sv_maxclients 20
set rconpassword "change-me"

set sv_pure 1                  // set to 0 if you run a mod pk3
set sv_allowDownload 1         // let clients pull missing paks
set sv_maxRate 25000
set sv_fps 20
set sv_timeout 60

set g_allowVote 1
set g_antilag 1
set scr_friendlyfire "0"
set scr_killcam "1"
set g_deadChat "1"
set logfile 0
set g_log "games_mp.log"
set g_logsync 0

set scr_dm_timelimit "10"      // MINUTES, not seconds
set scr_dm_scorelimit "150"

set sv_mapRotation "gametype dm map mp_harbor map mp_chateau map mp_depot"
map_rotate

Two traps in that file:

• rconpassword is one word on CoD1 and CoD:UO. CoD2 and later renamed it to rcon_password. Using the wrong one silently leaves rcon disabled.
• scr_dm_timelimit is in minutes, and any non-zero value is clamped to 1440. 0 means unlimited and is not clamped. Setting it to 1 while you are testing will restart the map underneath connecting clients mid-download.

The full list is on the CoD server cvar reference, and you can build a config without typing it by hand with the server.cfg generator.

Starting the server

cd /opt/cod1
./cod_lnxded \
  +set fs_basepath /opt/cod1 \
  +set fs_homepath /opt/cod1 \
  +set dedicated 2 \
  +set net_port 28960 \
  +set sv_maxclients 20 \
  +set rconpassword "change-me" \
  +exec server.cfg \
  +map mp_harbor

dedicated 2 means "internet server, send heartbeats to the master". dedicated 1 is LAN only and will never appear in the public browser.

On a 64-bit kernel wrap the call in setarch i386 -R to disable address-space randomisation. The 2004 binary predates ASLR and occasionally faults without it:

setarch i386 -R ./cod_lnxded +set dedicated 2 ...

Healthy startup log

Sys_LoadDll(/opt/cod1/main/game.mp.i386.so)... ok
Sys_LoadDll(game) succeeded!
------- Game Initialization -------
gamename: Call of Duty
gamedate: Nov 15 2004
COD MP 1.5 build linux-i386 Nov 15 2004

30172 files in pk3 files is the normal handle count for stock paks plus one mod pak.

systemd unit

[Unit]
Description=Call of Duty 1 dedicated server
After=network-online.target

[Service]
Type=simple
User=cod
WorkingDirectory=/opt/cod1
ExecStart=/usr/bin/setarch i386 -R /opt/cod1/cod_lnxded \
  +set fs_basepath /opt/cod1 +set fs_homepath /opt/cod1 \
  +set dedicated 2 +set net_port 28960 \
  +exec server.cfg +map mp_harbor
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target

If you would rather not install 32-bit libraries on the host at all, see running Call of Duty servers in Docker.

Getting listed in the server browser

CoD1's Activision master, codmaster.activision.com:20510, is still answering in 2026 and is what the in-game and Steam browsers query. Leave sv_master1 alone and it is used automatically. The heartbeat's source IP becomes the advertised address, which means the listing works through port-preserving NAT but not through a proxy that rewrites the source.

cod.pm runs a community master and a web server list, useful as a cross-check when you are not sure whether your heartbeat is landing.

To suppress master registration entirely (private or LAN server):

set sv_master1 ""
set sv_master2 ""
set sv_master3 ""
set sv_master4 ""
set sv_master5 ""

Map rotation

sv_mapRotation is a flat token list, not a JSON array:

set sv_mapRotation "gametype dm map mp_harbor map mp_chateau gametype tdm map mp_carentan"

Valid tokens are gametype, map, exec, allow_jeeps, allow_tanks. The engine consumes sv_mapRotationCurrent from the front as it advances. Details and the force-next-map trick are in the map rotation guide.

The 16 stock map codes are listed on the Call of Duty map list.

Installing a mod

CoD1 mods are .pk3 archives (plain zip files) dropped into main/.

1. The extension must be .pk3. The 1.5 engine only scans *.pk3 in the gamedir. .iwd is CoD2 and later; a correctly built .iwd will sit there being ignored.
2. Paks load alphabetically and the last one wins for duplicate paths. Prefix your mod zz_ so it overrides pak0…pakb.
3. On 1.1, use zzz_ or zzzz_ instead. The 1.1 server does not load a zz_-prefixed pak. Identical bytes named zzzz_ load fine. This one costs people hours.
4. Set sv_pure 0 whenever you ship a mod pak, unless you have specifically tested the pure-checksum path.

Full details in installing Call of Duty mods, and the download-to-client side in fast download.

Client autodownload on 1.1

1.5 clients download missing paks over UDP as soon as sv_allowDownload 1 is set. 1.1 clients default to cl_allowDownload "0", so an out-of-the-box client refuses.

CodExtended works around this by registering cl_allowDownload with the CVAR_SYSTEMINFO flag, so the server's value propagates into the client's systeminfo and its local copy flips to 1. With CEx loaded:

set sv_pure 0
set sv_allowDownload 1
set sv_fastDownload 1    // CEx only: 2 KB -> 8 KB UDP blocks, ~4x faster
set cl_allowDownload 1   // CEx flags this CVAR_SYSTEMINFO so it reaches clients

Load CEx by preloading the shared object:

LD_PRELOAD=/opt/cod1/codextended.so ./cod_lnxded +set dedicated 2 ...

A stock 1.1 server cannot do this. Without CEx your only options are asking players to set cl_allowDownload 1 themselves, distributing the pak out of band, or writing the mod so it needs no client-side files at all.

Remote administration

rcon <password> status
rcon <password> map mp_carentan
rcon <password> kick <playername>

CoD's rcon runs behind flood protection: two commands inside roughly 500 ms collapse, and the second comes back as Bad rconpassword. or an empty reply, which is indistinguishable from a wrong password. Space commands 600 ms apart and read cvars back after setting them. The rcon guide has the wire format and a working Python snippet.

Common problems

• libstdc++.so.5: cannot open shared object file
• Server appears offline / not in the master list
• EXE_SERVER_IS_DIFFERENT_VER
• Awaiting Challenge / Awaiting Connection
• Couldn't load default.cfg
• Full error index