I've just tried a couple of permutations on this theme, but haven't managed to get them to work. I have an Apple Airport Extreme router and I think it's being strict about its MAC switching and will not tolerate the same MAC on both WAN and LAN interfaces.

Does anyone have a method which will work?

Paul - if you mean the DD-WRT firmware, they've got a solution for this:

http://www.dd-wrt.com/wiki/index.php/Access_To_Modem_Configuration

I'm using a similar technique with a Netscreen firewall to access a Vigor 100's web interface:

1. Set up the Untrust interface (ethernet0/0) with a 192.168.1.x address in the same subnet as the Vigor 100 ;

2. Set up the PPPoE connection on a subinterface (ethernet0/0.1) ;

3. Create a policy to route traffic to the Untrust interface - this will require a policy with NAT, your mileage may vary depending on network topology.

Chris

Yes - DD-WRT - will take a look that thanks.

Paul