DNS need some explaination

Hello Linux gurus, I am confused. The situation is like this:

We have a mail/web server which is behind a firewall/router ( linksys ).
It has has been setup to serve as a sub-domain of our company. This
server can be accessed via ssh/web and can receive incoming mail.
Looking at the DNS entries on dreamhost.com and thru 'dig' the IP
address is same with the public IP of our router. How can the router
knows which of the machines (servers and our workstations) is the
destination during http/mail/ssh request? The router administration page
doesn't give any clue. I am trying to duplicate this behaviour by
registering another sub-domain pointing to my machine but using the
routers IP. However, it seems that whenever I access this new subdomain
via http it still points to the same server (original).

Can anybody enlighten me on this? Thanks so much!

Jun

-- 
Raul Martinez Jr. <[email protected]>

_________________________________________________________
Philippine Linux Users' Group (PLUG) Newbie Mailing List
[email protected] (#PLUG @ irc.free.net.ph)
Read the Guidelines: http://linux.org.ph/lists
Searchable Archives: http://archives.free.net.ph