Oracle Database Express Edition (XE)

I have Oracle XE installed on a box running Oracle Enterprise Linux 5.3 (64bit). It took quite a bit of effort to get it set up, but I got there in the end. I have upgraded the default Apex 2.2 installation to Apex 3.2.1 and configured it to use the embedded PL/SQL gateway on port 8500. I used port 8500 because I also have Apache Tomcat running and that is using port 8080.

My problem is that I can access the Apex web interface using the URL http://localhost:8500/apex, but not when I use the static IP assigned to my workstation which is 10.0.0.6. When I try the URL http://10.0.0.6:8500/apex, Firefox gives the error 'Firefox cannot establish a connection to the server 10.0.0.6:8500'.

I have tried turning off the system firewall but get the same problem. I also have SELinux installed, but it is running in permissive mode.

I think this is an Oracle XE/Apex related problem because I can access the Tomcat homepage by using either localhost or the IP 10.0.0.6 in the URL - therefore I think this rules out any firewalling/security issues.

I would like to be able to access the Apex set up from other computers, so it is quite important to get this problem resolved.

Does anyone have any ideas what the problem may be?