D-Link DSL-2740R Routing only from internal IP?

Question

I have the router listed in the title which I bought for a wireless network at work. It's a modem/router but I only want it for routing. D-Link's support tell me I can't do this.

I've had it working with the incoming internet (supplied by the offices we are in, we are given an IP) into one of the LAN ports and a laptop plugged into another. It successfully routes through, but this causes the router (192.168.1.1) to be un-pingable. Also, the setup utility won't allow me the required IP (invalid IP address) 172.16.244.0

Am I fighting a lost cause?

Answer 1

Give the router an IP on the same range as your LAN for a start, that should let you access the web interface.