I've got an odd PPPoE packet redirection networking problem

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http://www.linuxquestions.org – I have a machine with two network cards running linux mint 8 XFCE (which is compatable with Ubuntu Intrepid Ibex). eth0 gos out onto the network propper, has a static IP address of and serves DHCP requests for the 10.10.10.x subnet. eth1 is pluged into a PPPoE concentrator, and has a static address of (I would have left it alone but pppoeconf wouldn't work unless it had an address). ppp0 is the piont to piont over ethernet conection that is corectly created when I run pon. I have both guard dog and guide dog installed but they are both disabled. Now, the weird part: I can ping the IP number of the machine at the other end of the pppoe conection (when it changes I can still ping the new number), the local IPs (10.10.10.x), but *nothing* else not even the DNS servers passed to the machine during ppp conection which are in the same sub net as the machine I can ping. When I try to ping or trace the route I get an error message like: reply from desination unreachable There is nothing wrong with the network at the other end, as I can make an Identical PPPoE connection from other machines on the network if the the concentrator is pluged into the hub (a rather unsafe place for it to be) and it all just falls into place. What seems to be happening is that the machine is treating eth0 rather than ppp0 as the internet gateway, and passing the packets round in circles. Can anyone give me some idea how to fix this? (HowTos)