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. The following guidelines pertain primarily to Enterprise Server:
In general, firewalls should be configured 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 set up for port 8081, you must configure the firewalls to allow HTTPS requests on port 8081.
If direct Remote Method Invocations over Internet Inter-ORB Protocol (RMI-IIOP) access from the Internet to EJB modules is required, open the RMI-IIOP listener port as well.
Opening the RMI-IIOP listener port 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 Enterprise Server behind the firewall.