I've got a four port linksys router at home, connected to a DSL line,
providing access to a couple powerbooks. I've got five static IP
addresses on this DSL line, and I'd like to add a linux box to serve
up some web pages, do ssh, be a nameserver, and act as a mail server
(it will require two IPs for the nameservers).

I've had the identical setup previously working at my last residence,
but I used a small four-port hub in front of the linksys router. Under
this configuration, the linux box had two of the external IPs (and was
entirely exposed on the internet -- don't worry it's patched and
solid), then the router took a third and used that for the rest of the
client network.

What I want to try now is two eliminate the four port hub before the
router. I know I can give the linux box an internal IP, then use the
DMZ option to expose it online. I've read the linksys support docs,
and they state that the DMZ machine won't share the IP address, but it
doesn't say anywhere how it obtains IPs or where you can set them.
Ideally, I'd like to give the linux box two external IP addresses that
are different than the static IP on the wan port of the linksys. I
can't figure out if the linux box should carry a single internal IP
(that maps to the DMZ on the router) and two additional external ones,
and if it will correctly respond.

So, is there anyway I can get two external IPs on a linux box, and
have that box externally viewable on the internet, while also being
connected to my linksys router with the DMZ option enabled on it?