D-link router and network settings

I have a Mac that is hooked up to my D-link **-524 router directly via ethernet cable. My D-link router is in turn hooked up to my Linksys voice over internet router which is then connected to my Westell Modem (verizon dsl). I also have a PC that is successfully remotely accessing the internet via the dlink router. However, my Mac can only access the internet when I bypass the dlink router and connect directly to the modem. I cannot access the configuration page 192.168.0.1 in order to upgrade my firmware--I get the message "could not find a PPPoe server".

When I go the Network status I get the follwing messages:
Built in Ethernet is set up to use PPPoe. Built in EThernet is plugged in but not connected. "Connect Automatically" is selected.
VPN (L2TP) is configured, but is not connected.

I think that I have changed my network settings either by screwing around with the settings or when I performed an A&I and reinstalled OSX. Do I want to connect via PPPoe or DHCP?

I called D-link tech support 3 times and finally was told they don't know OSX 10.4!!!! I have also called Verizon and Vonage Tech Support and am told they can't help me since their systems are working ok. I feel like I am being ping-ponged around and don't know what to do next.
Can someone please tell me what network settings I need???