>If the modem can be told to pay attention to only one of them, you are
>probably OK.  But if not, you are at risk of exposing your internal
>traffic to the outside world, with all the consequences that entails.

This is not true for most residential DSL installations in the US, 
which are usually PPPoE. That is all that the modem will pay 
attention to, regardless of the originating interface. Since only one 
interface will be running a PPPoE client (the NetBSD router) all 
other machines on the LAN are quite invisible to the outside world 
except where the router is explicitly told to allow otherwise via NAT 
tables.

The original poster is in Italy and you're in Canada, and I have no 
knowledge or expertise in what is common practice in those countries, 
but it's easy enough to ask the DSL provider whether they provide 
straight IP connections on the Ethernet or whether it's PPPoE in 
order to make the decision about the router. Or you can even find out 
by looking in their self-help Tech Support section of the website. If 
it has, for instance, downloads for MacPoET, then it's a PPPoE setup 
:).

Mike
-- 
Bikers don't *DO* taglines.