Were you able to ping the Apex?
On your computer, open any web browser and type in " apex," if you changed the port forwarding enter "apex: (Port number)" no spaces in between, then enter.
It should prompt you for a password which is defaulted as the following;
Username : Admin
Password : 1234
To find the IP address, using windows OS.
Click on Start > Run > Type in cmd > In the black window/dos screen type "ipconfig /all" to show your IP, DNS, Gateway, MAC etc.
The Apex should be a defaulted IP address.
192.168.1.1
If you want to give it a static IP ( Which you should, if you're using it web based ) make sure to forward the ports via your router.
Otherwise you're going to have a hell of a nightmare if you have multiple IP devices using DHCP, example : your roommates being on the wireless network. It's like VPN where there's a set of numbers lined up for usage.
The E2000 does a good job of that, I have the E3000 so it's not that much of a difference.
In order to get to your router, IP configure your address and type it in the web browswer, the last number being a 1.
Example : 192.168.1.1
Hope that helps.