Ok, I'll just tell you how my network is set up.
I have a DSL wifi router.
I use a PPPoE connection with a username and password to connect to my ISP - mweb in my case usually.
Then my router sits at 10.0.0.1 on the LAN. So thats how I get the settings etc too, open browser, 10.0.0.1 -> off I go.
It then acts as a DHCP sever for any new devices and assigns IP's in the range 10.0.0.33 - 10.0.0.65 (so can allow 32 devices). Then all my static IP devices sit below the 33 range.
On my Xbox, the IP is a static 10.0.0.10, Gateway is 10.0.0.1, DNS server 10.0.0.1 (both point to my router), subnet mask is 255.255.255.0. PPPoE settings are not set.
I then forward the ports for my xbox to get my NAT to open.
It would be exactly the same for a PS3. I could have a PS3 @ 10.0.0.11. No need for a PPPoE connection on it as the router is already connected to the net.