[Off-Topic] Two class C networks

["Jordi S. Bunster" <jsb@expert.com.br>]

Hello list. This is probably off-topic, though is Debian in an ISP
environment. I don't know. Problem follows:

I've got a Debian box acting as a webserver at a small ISP here, and
connection is a 1mbps fiber link. They've given us a full Class C network
for some other purposes. But we're planning on switching bandwidth provider,
and the new one already brought his link and router.

The thing is, I've put a second network card, and I've attached it to the
server. The new router is on a different hub. I can use this new link if I
use my Debian box to connect to somewhere in the world, say mit.edu. But
people from outside cannot reach me using this new IP address.

I know this is because of the entry "gateway" in /etc/network/interfaces.
This come trough the new router, but it wants to reply using the gateway,
which is the old router.

How can I properly have both network cards and both IPs, and be able to be
found by both of them? I'm really puzzled here. Thanks for any help, and
sorry for being so off-topic. Oh, and I'm not subscribed to the list, so
please Cc: to jsb@expert.com.br, ok?

 -- Jordi S. Bunster