I'm not sure this actually is a port related issue. The "blank page" error is usually related to improper configuration of the static contents ("images") for APEX. I'd recommend to check the steps in the Installation Guide that corresponds to the APEX Listener version you are trying to get up. Make sure you read the section that is intended for the JEE container you use, as different containers may require different configuration steps.
(In any case, you should provide such information as product and platform version when posting about an issue... It makes helping you much easier.)
if anyone could help, I am having issues locating the images in the APEX listener zip file. This is what I downloaded - apex_listener.18.104.22.168.14.47.zip
Documents say I need to copy the image files. I did a recursive find for images and copied it to static location and configured this - java -jar apex.war static <>path_to_apex/images. Compiled i.war and no luck with images.
I tried this on GlassFish & Tomcat. What am I missing here to load images?