> In bridge mode, the DSL modem is just that, a modem.  Your 
> Linux front end appears right on the network.  No Nat, 
> Firewall, etc.  Those functions are handled by Linux 
> (masquerading=NAT).  It also eliminates the address 
> translation problems that hinder VPN.  I use to have 
> MNinter.net, but they forced me (without prior notice) to 
> switch to router mode which broke our VPN after 2 weeks of 
> arguing with them I switched.  

Keep in mind that PPP mode can work in both a NAT setup, or a routing setup.
In the NAT setup, all of your public IP's get assigned to the WAN interface
on the DSL modem.  In route mode, only one of your IP's get's assigned to
the WAN interface, and it routes the packets for your other addresses to the
inside interface.  If your ISP gives you multiple ip's, you can make it
route instead of doing NAT, so your machines actually get public IP's.  Of
course, if you do this, you'd better make sure the machines are locked down
tight.  Or you can assign the public ip's to a firewall, obviously.  :)

Jay