CS:GO AMP server only accessible locally – external connections fail with error 10

OS Name/Version:
Debian 12 (running as VM under Proxmox VE 8.3)

Product Name/Version:
AMP (Application Management Panel) — CS:GO Dedicated Server Instance
AMP build: latest (as of 04/10/2025)


Problem Description:
External players cannot connect to my CS:GO Dedicated Server through a public IP (using reverse proxy via localtonet).
When I connect from my local network using the local IP, everything works correctly.
When I connect from my local network but using the external/public IP through localtonet, it also works fine — I can join the server without issues.
However, when my friends try to connect using the same external/public IP (through localtonet), they immediately get dropped with the following Steam authentication error:

STEAMAUTH: Client Ex1r4 received failure code 10
STEAMAUTH: Client _DemoKnight_ received failure code 10
disconnected (reason "Client dropped by server")

My own account (“egore4606”) connects successfully with no SteamAuth errors.


Steps to reproduce:

  1. Run a CS:GO Dedicated Server instance in AMP on a Debian 12 virtual machine (under Proxmox VE).

  2. Expose only port 27015 externally via localtonet (reverse proxy).

  3. Try connecting to the server:

    • From inside the local network via local IP → works.

    • From inside the local network via external IP through localtonet → works.

    • From an external PC (friend) via the same public IP through localtonet → fails.

  4. Observe the “STEAMAUTH failure code 10” errors in AMP console logs for external clients.


Actions taken to resolve so far:

  • Restarted both the CS:GO server and the entire AMP instance.

  • Verified the game files and updated via SteamCMD.

  • Tried restarting Steam services and checking authentication status.

  • Opened port 27015 in both the router and firewall (localtonet also confirms it’s exposed).

  • Tested both TCP and UDP exposure on port 27015.

  • Confirmed that connecting through the external IP works only locally, not for remote clients.

  • Verified that the “Your server needs to be restarted…” message persists even after restarts.


Full relevant log excerpt:

10/04/2025 - 17:22:21: STEAMAUTH: Client Ex1r4 received failure code 10
10/04/2025 - 17:22:21: "Ex1r4<2><STEAM_1:1:517164706><>" disconnected (reason "Client dropped by server")
10/04/2025 - 17:22:31: Your server needs to be restarted in order to receive the latest update.
10/04/2025 - 17:23:12: "_DemoKnight_<3><STEAM_1:0:577153701><>" connected, address ""
10/04/2025 - 17:23:13: STEAMAUTH: Client _DemoKnight_ received failure code 10
10/04/2025 - 17:23:13: "_DemoKnight_<3><STEAM_1:0:577153701><>" disconnected (reason "Client dropped by server")
10/04/2025 - 17:23:23: Your server needs to be restarted in order to receive the latest update.
10/04/2025 - 17:24:10: "egore4606<4><STEAM_1:0:578579696><>" connected, address ""
10/04/2025 - 17:24:11: "egore4606<4><STEAM_1:0:578579696><>" STEAM USERID validated
10/04/2025 - 17:24:18: "egore4606<4><STEAM_1:0:578579696><>" entered the game
10/04/2025 - 17:24:20: Your server needs to be restarted in order to receive the latest update.

OS Linux
Platform Debian GNU/Linux 12
System Type x86_64
Hardware Platform SeaBIOS Standard PC (i440FX + PIIX, 1996)
CPU Model QEMU Virtual CPU version 2.5+
CPU Layout 1S/6C/6T
Installed RAM 7756
Virtualization Docker
Network Mode Host Mode
Module GenericModule
Module Application Counter-Strike: Global Offensive
Loaded Plugins FileManagerPlugin, EmailSenderPlugin, WebRequestPlugin, WebhookPlugin, LocalFileBackupPlugin, CommonCorePlugin, AnalyticsPlugin
Application Name AMP
Application Version 2.6.3.0
Codename Phobos
Tools Version 2.6.2.4
Release Stream Mainline
Build Spec Release
Build Date 26/09/2025 12:10
InstanceID 3ca9fd2e-4c71-478b-82d9-02bf8fa34c76
Last Executable /AMP/csgo/740/srcds_linux
Last Arguments -game csgo -console -usercon -nobreakpad -port 27015 -ip 192.168.178.111 -maxplayers_override 8 -authkey ********** -tickrate 64 -insecure -nohltv +tv_port 27020 +sv_logfile 1 +sv_pure 0 +exec server.cfg +map de_dust2 +game_type 0 +game_mode 0 +sv_game_mode_flags 0 +sv_skirmish_id 0 +log on +logaddress_add 192.168.178.111:34855
Last Process ID 205

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.