> If this is the case, a workaround would be to set the default gateway on
> the clients to the Linux router, and let the router reroute the packets to
> the DSL.  Not 100% optimal since the packets go over the same network
> twice, but you're talking about a DSL line, I don't think it's going to
> severely impact performance on a 100M LAN.

will linux route packets like this? i feel like I've tried it before
and it refused to route them and send out icmp redirects instead,
although that might solve your problem too.