I have two routers, one of them was provided by my ISP, and I have another one that I flashed with DD-WRT. The ISP router has wireless capabilities, but I'd like to shut it down and use my flashed router as the wireless access point. The ISP router will only serve as a way for my flashed router to access the internet.
The trouble is, I don't know how to configure my flashed router to allow internet access for connected hosts. At first I tried plugging a cable from one of the LAN ports on the ISP router to the internet port from the flashed router. Then, following this post, I tried plugging it into one of the LAN ports in the flashed router, instead of the internet port. But still my computer connected to the flashed router didn't have access to the internet.
How should I connect the routers, and which values should I set for the flashed router configurations?
EDIT: My ISP router is a D-LINK DSL-2730B and my flashed router is a Linksys WRT54G V8