The only reason i could think of as to why it is required, is if its ip
address isn't 10.0.0.1 as you think it is and for some strange reason it
accepts ip packets as its own if the ethernet header points to its MAC
address... try setting it to DHCP and see if you get an ip... else look up
the manufacturer for the default ip and try a factory reset
I think things are going overboard here, Im just going to give up.
I have tried it with pppoe being down, still couldnt connect to the modem.