Trying to learn something but not sure what to Google...

[jack-rp9/bkPP+cDYtjvyW6yDsg at public.gmane.org (Jack Coats)]

On Sun, Sep 12, 2010 at 10:36 PM, Edward Ned Harvey <blu-Z8efaSeK1ezqlBn2x/YWAg at public.gmane.org> wrote:
>> From: discuss-bounces-mNDKBlG2WHs at public.gmane.org [mailto:discuss-bounces-mNDKBlG2WHs at public.gmane.org] On
>> Behalf Of Jarod Wilson
>>
>> > You can't forward a single inbound IPaddress/port to two separate
>> (and
>> > different) internal websites.
>>
>> Yes, actually, you can (been there, done that). However, it requires a
>> web server running on the gateway system, proxying them.
>
> I think that's what I said. ?You can't NAT to two separate and different
> internal IP's & ports, but you can NAT to a single one, which then knows how
> to forward/redirect/proxy whatever page was requested. ?But the fact
> remains, this is still being handled by a single internal IP address and
> port, which is then choosing some other server(s) to use in reality.
>
> The handoff could either be a proxy (the machine that was the NAT
> destination is relaying traffic) or it could be a direct handoff, such as a
> redirect to a different IP address or port, or URL.

my little routers allow taking incoming ports and forwarding them to
any internal IP/port
combination I like.  But yes, it is a one to one mapping if I remember right.