TWS connects to IBKR servers via port 4000 and 4001, if using SSL, and will not operate on any other port. If you are using a proxy server, it needs to be a transparent with both inbound and outbound ports open so that the TWS can function properly.

Below are listed all the gateways, along with the corresponding destination host that might be used by the TWS when you use our services, please allow access to those hosts.

The easiest way to test whether your connection needs any special setup or has been configured properly is to use IBKR's Dedicated Test page, which will provide a dynamic test of your network’s connection against our main trading and market data servers. If a “Success” response is returned, there is nothing more for you to do. If the response is “Failure”, we recommend adding an exception for the new hosts to your network’s configuration or review your changes.

Note: If your network uses a browser proxy, the test page can produce false positives. In this case, or if you are not sure what your network setup is, turn to your network administrators, who can perform ping and telnet tests to the hosts listed below to confirm compliance with the connectivity requirements.