If you have an active firewall on the machine that is running your Directory Server and enterprise server instances, and you want remote clients to be able to connect to them, you must ensure that the firewall allows access to the ports that you are using.
For example, Directory Server is configured, by default, to use port 86. Your must configure your firewall to allow TCP and UDP access to this port. Similarly, the default enterprise server instance for most platforms, ESDEMO, has a Web Services and J2EE listener that uses port 9003. For remote clients to be able to submit requests to this listener, your firewall must permit access to this port.
We recommend that, if you want remote users to access Enterprise Server functionality through the firewall, you use fixed port values so that you can control access via these.