TRADING_MODE=both, live port works fine, paper port refuse connection

[KevinYum]

Describe the bug

with TRADING_MODE=both, live port(4001) works fine but paper port(4002) refuse connection

To Reproduce

docker-compose.yaml

name: algo-trader
services:
  ib-gateway:
    restart: always
    build:
      context: ./stable
      tags:
        - "ghcr.io/gnzsnz/ib-gateway:stable"
    image: ghcr.io/gnzsnz/ib-gateway:stable
    environment:
      TWS_USERID: ${TWS_USERID}
      TWS_PASSWORD: ${TWS_PASSWORD}
      TWS_PASSWORD_FILE: ${TWS_PASSWORD_FILE}
      TRADING_MODE: ${TRADING_MODE:-paper}
      TWS_SETTINGS_PATH: ${TWS_SETTINGS_PATH:-}
      TWS_ACCEPT_INCOMING: ${TWS_ACCEPT_INCOMING:-}
      TWS_MASTER_CLIENT_ID: ${TWS_MASTER_CLIENT_ID:-}
      READ_ONLY_API: ${READ_ONLY_API:-}
      VNC_SERVER_PASSWORD: ${VNC_SERVER_PASSWORD:-}
      TWOFA_TIMEOUT_ACTION: ${TWOFA_TIMEOUT_ACTION:-exit}
      BYPASS_WARNING: ${BYPASS_WARNING:-}
      AUTO_RESTART_TIME: ${AUTO_RESTART_TIME:-}
      AUTO_LOGOFF_TIME: ${AUTO_LOGOFF_TIME:-}
      TWS_COLD_RESTART: ${TWS_COLD_RESTART:-}
      SAVE_TWS_SETTINGS: ${SAVE_TWS_SETTINGS:-}
      RELOGIN_AFTER_TWOFA_TIMEOUT: ${RELOGIN_AFTER_TWOFA_TIMEOUT:-no}
      TWOFA_EXIT_INTERVAL: ${TWOFA_EXIT_INTERVAL:-60}
      TWOFA_DEVICE: ${TWOFA_DEVICE:-}
      EXISTING_SESSION_DETECTED_ACTION: ${EXISTING_SESSION_DETECTED_ACTION:-primary}
      ALLOW_BLIND_TRADING: ${ALLOW_BLIND_TRADING:-no}
      TIME_ZONE: ${TIME_ZONE:-Etc/UTC}
      TZ: ${TIME_ZONE:-Etc/UTC}
      CUSTOM_CONFIG: ${CUSTOM_CONFIG:-NO}
      JAVA_HEAP_SIZE: ${JAVA_HEAP_SIZE:-}
      SSH_TUNNEL: ${SSH_TUNNEL:-}
      SSH_OPTIONS: ${SSH_OPTIONS:-}
      SSH_ALIVE_INTERVAL: ${SSH_ALIVE_INTERVAL:-}
      SSH_ALIVE_COUNT: ${SSH_ALIVE_COUNT:-}
      SSH_PASSPHRASE: ${SSH_PASSPHRASE:-}
      SSH_REMOTE_PORT: ${SSH_REMOTE_PORT:-}
      SSH_USER_TUNNEL: ${SSH_USER_TUNNEL:-}
      SSH_RESTART: ${SSH_RESTART:-}
      SSH_VNC_PORT: ${SSH_VNC_PORT:-}
      START_SCRIPTS: ${START_SCRIPTS:-}
      X_SCRIPTS: ${X_SCRIPTS:-}
      IBC_SCRIPTS: ${IBC_SCRIPTS:-}
#    volumes:
#      - ${PWD}/jts.ini:/home/ibgateway/Jts/jts.ini
#      - ${PWD}/config.ini:/home/ibgateway/ibc/config.ini
#      - ${PWD}/tws_settings/:${TWS_SETTINGS_PATH:-/home/ibgateway/Jts}
#      - ${PWD}/ssh/:/home/ibgateway/.ssh
#      - ${PWD}/init-scripts:/home/ibgateway/init-scripts
    ports:
      - "127.0.0.1:4001:4003"
      - "127.0.0.1:4002:4004"
      - "127.0.0.1:5900:5900"

.env (exclude my password section which are correctly set and tested with live & paper mode seprately)

TIME_ZONE=Etc/UTC
###############################################################################
#########   Settings path and custom config, see documentation
#########   https://github.com/gnzsnz/ib-gateway-docker?tab=readme-ov-file#preserve-settings-across-containers
###############################################################################
# ib-gateway
# TWS_SETTINGS_PATH=/home/ibgateway/Jts
# tws
# TWS_SETTINGS_PATH=/config/tws_settings
# TWS_SETTINGS_PATH=
# if you need custom config
# https://github.com/gnzsnz/ib-gateway-docker?tab=readme-ov-file#customizing-the-image
# CUSTOM_CONFIG=
###############################################################################
#########   Java memory settings, see
#########   https://www.ibkrguides.com/traderworkstation/increase-tws-memory-size.htm
###############################################################################
JAVA_HEAP_SIZE=4096
###############################################################################
#########   IBC settings
#########   these are IBC settings passed to IBC's config.ini file
#########   for reference please visit
#########   https://github.com/IbcAlpha/IBC/blob/master/userguide.md
###############################################################################
# trading mode can be live,paper,both - both allows for parallel live and paper
TRADING_MODE=both
READ_ONLY_API=no
TWOFA_TIMEOUT_ACTION=restart
TWOFA_EXIT_INTERVAL=
TWOFA_DEVICE=
BYPASS_WARNING=yes
AUTO_RESTART_TIME=11:59 PM
AUTO_LOGOFF_TIME=
TWS_COLD_RESTART=
TWS_ACCEPT_INCOMING=
SAVE_TWS_SETTINGS=
RELOGIN_AFTER_TWOFA_TIMEOUT=yes
EXISTING_SESSION_DETECTED_ACTION=primaryoverride
ALLOW_BLIND_TRADING=no
#TWS_MASTER_CLIENT_ID=
###############################################################################
#########   VNC settings
###############################################################################
# VNC_SERVER_PASSWORD=myVncPassword
# see credentials section for more details
# VNC_SERVER_PASSWORD_FILE
###############################################################################
#########   SSH tunnel settings, see documentation
#########   https://github.com/gnzsnz/ib-gateway-docker?tab=readme-ov-file#ssh-tunnel
###############################################################################
SSH_TUNNEL=
SSH_OPTIONS=
SSH_ALIVE_INTERVAL=
SSH_ALIVE_COUNT=
SSH_PASSPHRASE=
SSH_PASSPHRASE_FILE=
SSH_REMOTE_PORT=
SSH_USER_TUNNEL=
SSH_RESTART=
SSH_VNC_PORT=
SSH_RDP_PORT=
###############################################################################
#########   Start scripts settings, see documentation
#########   https://github.com/gnzsnz/ib-gateway-docker?tab=readme-ov-file#start-up-scripts
###############################################################################
#START_SCRIPTS=init-scripts/start_scripts
#X_SCRIPTS=init-scripts/x_scripts
#IBC_SCRIPTS=init-scripts/ibc_scripts

Expected

4001 and 4002 can be connected to live and paper mode Gateway

Container logs

when connecting to paper (4002):

ib-gateway-1  | 2025-11-14 08:25:35:920 IBC: detected dialog entitled: IBKR Gateway; event=Activated
ib-gateway-1  | 2025-11-14 08:25:35:921 IBC: detected dialog entitled: IBKR Gateway; event=Focused
ib-gateway-1  | 2025-11-14 08:25:35:923 IBC: detected dialog entitled: IBKR Gateway; event=Lost focus
ib-gateway-1  | 2025-11-14 08:25:35:924 IBC: detected dialog entitled: IBKR Gateway; event=Deactivated
ib-gateway-1  | 2025-11-14 08:25:35:931 IBC: detected dialog entitled: IBKR Gateway; event=Closed
ib-gateway-1  | 2025-11-14 08:25:35:932 IBC: detected dialog entitled: U****** Trader Workstation Configuration; event=Closed
ib-gateway-1  | 2025-11-14 08:25:36:265 IBC: detected dialog entitled: Pending Tasks; event=Closed
ib-gateway-1  | 2025/11/14 08:25:46 socat[356] E connect(5, AF=2 127.0.0.1:4002, 16): Connection refused

when connecting to live (4001):

ib-gateway-1  | remove Client 2

all api works fine

Versions

Please complete the following information:

• OS: Linux server
• Image Tag (docker image inspect ghcr.io/gnzsnz/ib-gateway:tag): stable
• Image Digest (docker images --digests): sha256:37e86ffee6ddc269265ddb8d3b39a286a778fdb9c6d3a7baec0ebbe30f8efbc2

[gnzsnz]

please paste the full log. make sure that you see IBC: Logging has completed twice as live and paper need to connect.
with the information provided i can't help you. please provide your full .env file, you can remove your user name and password, but i need to see how you setup parallel mode. you have removed key information and provided me with an .env file that is not giving me any information.

please use the docker compose provide as example the one you are using is simplified, it works but will not work for parallel mode, because you are not passing TWS_USERID_PAPER and TWS_PASSWORD_PAPER this is explained on the README.md

So most probably your problem is the docker-compose.yml that you are using.

[KevinYum]

Apart from this issue,
I tried also to restart two docker container separately with "live" and "paper" mode.
I can connect to both container well but it is expected that "paper" container will not have market data feed when the "live" container is running.
And I believe this is the reason we need the "both" mode when the "paper" side can "forward" the market data from the same Gateway.

[gnzsnz]

have you checked with VNC the status of each ibgateway instance?

I only see "Login has completed" once, i guess it's from live, have you verified the status of your paper account, both in the log and with VNC? VNC is there to sort out issues, give it a try.

check if the ports are actually open on the host, #245 (comment)

TWS_USERID_PAPER is different from your live account, make sure that you enter your paper account not your live account. Using your live account on paper mode will not work

[KevinYum]

"TWS_USERID_PAPER is different from your live account, make sure that you enter your paper account not your live account. Using your live account on paper mode will not work"

Does this only apply to "both" mode? As I did succeed to use my live user/pass in "paper" mode of your docker image, as well as when I deploy IBC + IBGateway on my own;
Though I also tried paper user/pass in "paper" mode and it worked out as well.

check if the ports are actually open on the host, #245 (comment)

I did this docker compose check and it shows no error:
ubuntu@ip-172-26-6-46:~/wenkang/ib-gateway-docker$ timeout 1 bash -c '</dev/tcp/0.0.0.0/4002 && echo "TWS API up" || echo "TWS API down"' || echo "Connection timeout"
TWS API up

I only see "Login has completed" once, i guess it's from live, have you verified the status of your paper account, both in the log and with VNC? VNC is there to sort out issues, give it a try.

Will try this and reply, as currently I'm running on VPS and it may take a while to set it up.

[gnzsnz]

https://www.interactivebrokers.com/campus/trading-lessons/how-to-open-an-ibkr-paper-trading-account/