How to check and solve connectivity issues affecting TWS?

IBKR Servers

The IBKR Servers used by the TWS are listed in the table below, according to their location and role:

Windows

1. Press the Windows logo + R keys on your keyboard
2. Type "cmd" in the search box
3. Hit Enter on your keyboard
4. Type the following command, respecting the spacing:  ping -n 20 ndc1.ibllc.com
5. Hit Enter on your keyboard
6. Once the command has completed, check the Ping statistics. If the count of Packets:Lost  is above 0 or if the Maximum or Average round trip time value is above 400 ms, please contact your network administrator for further troubleshooting. You should do the same if the ping command returned “Request timed out” or “Destination host unreachable“ or “Could not find host...”. In any other case you can consider the test as successful and proceed with the next step
7. Type the following command, respecting the spacing:  telnet ndc1.ibllc.com 4001
8. Hit Enter on your keyboard. The following outcomes are possible:
   1. The window goes blank with no message and just a blinking cursor on the top. This means that your test was successful, and you can connect to the server through port 4001. Press CTRL+C on your keyboard to exit the command
   2. You receive the message "connecting to ..." and/or "connect failed". This indicates that the destination TCP port 4001 is unreachable. In this case, please contact your network administrator and request a change of your firewall rules to allow outbound connectivity towards all the Host Names and Ports mentioned in the table at the top of this page.
   3. You receive the message "'telnet' is not recognized as an internal or external command...". You need to enable the Telnet Client. Press the Windows logo + R on your keyboard, then type "cmd" in the search box and, in the panel on the left, select the option Run as Administrator. If a pop-up appears, asking you to allow the operation, click "Yes". Now type in the Command Prompt window the following command, respecting the spacing: DISM /online /enable-feature /featurename:TelnetClient and hit Enter on your keyboard. If the Telnet Client cannot be enabled because of lack of Administrative rights or credentials, please refer to your local IT Support Team. If the Telnet Client could be successfully enabled, please follow again the instructions, from step 7) onward.
9. Repeat the above steps from 1 to 8 for the remaining PRIMARY servers, by replacing ndc1.ibllc.com with the next hostname (e.g: cdc1.ibllc.com) in the steps 4) and 7), while preserving the rest of the parameters. Should you need to test as well the market data connections, please replace port 4001 with 4000 in point 7) while preserving the rest of the parameters.

macOS

1. Click on the Spotlight Search (the magnifying glass icon) on the top right corner of your Desktop
2. Type Terminal in the search box
3. Select the Terminal app from the list
4. Type the following command, respecting the spacing:  ping -c 20 ndc1.ibllc.com
5. Hit Enter on your keyboard
6. Once the command has completed, check the Ping statistics. If the count of Packets:Lost  is above 0 or if the Maximum or Average round trip time value is above 400 ms, please contact your network administrator for further troubleshooting. You should do the same if the ping command returned “Request timed out” or “Destination host unreachable“ or “Could not find host...”. In any other case you can consider the test as successful and proceed with the next step
7. Type the following command, respecting the spacing:  nc -vz ndc1.ibllc.com 4001
8. Hit Enter on your keyboard. The following outcomes are possible:
   1. You receive the message "Connected to….succeeded". This means that your test was successful, and you can connect to the server through port 4001
   2. You receive the message "...Connection refused”. In this case, please contact your network administrator and request a change of your firewall rules to allow outbound connectivity towards all the Host Names and Ports mentioned in the table at the top of this page.
9. Repeat the above steps from 1 to 8 for the remaining PRIMARY servers, by replacing ndc1.ibllc.com with the next hostname (e.g: cdc1.ibllc.com) in the steps 4) and 7), while preserving the rest of the parameters. Should you need to test the market data connections, please replace port 4001 with 4000 in point 7) while preserving the rest of the parameters.

Technical Notes

• The servers designated with ROLE: PRIMARY are used for authentication, trading operations and market data distribution. To function properly, the TWS needs direct access to the server where your account is based (on TCP Port 4001) and as well to the one/s distributing the market data you are consuming within the platform (on TCP Port 4000).
• The servers designated with ROLE: BACKUP would be used in a Disaster Recovery event. While it is fundamental that your TWS can access the BACKUP servers in such scenarios, the same is not a strict requirement for the daily operation of your TWS under normal circumstances.
• The PRIMARY server mcgw1.ibllc.com.cn and its correspondent BACKUP host mcgw1-hb1.ibllc.com.cn are only accessed when your connection originates from Mainland China. Unless you are connecting from Mainland China, you can skip the connectivity tests towards those two hosts.
• The fact you cannot reach one or more server may not necessarily represent an issue for your specific setup. For example: your account is based on the European server and you do not trade Asian financial contracts but only European and US (NYSE/NASDAQ) ones. In this scenario, it is fundamental for you to have a good connectivity towards to zdc1.ibllc.com (for authentication and trading operations) and ndc1.ibllc.com (for NYSE/NASDAQ Market Data), as your TWS would not need to connect to any other hosts.
• Corporate environments and Proxy server users: concerning the interaction between TWS and Proxy servers, please refer to this page.
• -vz will provide verbose output(-v) and will scan for listening services without sending data (-z).