A firewall controls the flow of data between two or more networks, and manages the links between the networks. A firewall can consist of both hardware and software elements. This section describes some common firewall architectures and their configuration. The information here pertains primarily to the Application Server. For details about a specific firewall technology, refer to the documentation from your firewall vendor.
In general, configure the firewalls so that clients can access the necessary TCP/IP ports. For example, if the HTTP listener is operating on port 8080, configure the firewall to allow HTTP requests on port 8080 only. Likewise, if HTTPS requests are setup for port 8181, you must configure the firewalls to allow HTTPS requests on port 8181.
If direct Remote Method Invocations over Internet Inter-ORB Protocol (RMI-IIOP) access from the Internet to EJB modules are required, open the RMI-IIOP listener port as well, but this is strongly discouraged because it creates security risks.
In double firewall architecture, you must configure the outer firewall to allow for HTTP and HTTPS transactions. You must configure the inner firewall to allow the HTTP server plug-in to communicate with the Application Server behind the firewall.