It sounds like you are trying to use, perhaps the ElkRM software from a location outside your LAN/home? Or perhaps the ethernet webpage from the ethernet module?
I have no experieince with ElkRM, but you probably want to try it from inside your network first to make sure it is working.
Once that is done, it is probably an issue of port forwarding. I have not exposed mine, but port 2601 sticks in my head (look at the manual for whichever solution you are trying to expose). Take a look at how to setup port forwarding on your router, and forward whatever ports are required to the IP address of your Elk.
If you know the ports, and are having trouble with your router, the manufacturers will typically have a support line and can walk you through it step by step. Or just check the manual for the product you have.
Hope this helps.