Router for Multiple IP Addresses -- IIS

I have set up a Win 2003 STD server hosting 2 VMs in a Virtual Server
environment. I want incoming http requests to be routed to the
appropriate IIS on one or the other of these 2 VMs, depending on
domain name, such that www.name1.com goes to VM #1 and www.name2.com
goes to VM #2.

I would prefer to accomplish this by way of multiple IP address (DNS
obviously resolving domain name to proper IP) and letting a hardware
router send the incoming requests to the proper server, based on the
IP address. My problem is my current router (a cheapo LinkSys) does
not handle more than one IP address. I can only do port forwarding,
and that's not good enough. Can someone recommend a suitable 'small
business' class router, or perhaps another solution? I've done
searches and not coming up with much. I'd be grateful. thanks, Nick

Nick,
If you will forgive me, it is a slightly unusual question because all the
usual router products, like Cisco and Netgear, will do this and so I am left
thinking there must be something more to your reason for asking. Are you
just looking for a product recommendation? The small Cisco's are excellent,
and if you are going to host web sites you may want to use the other
facilities like VLANs, access-lists, VPN's etc.
You will also need more IP addresses from your ISP.
Finally, you can just host multiple addresses on one server and one IP using
host headers, so I am not sure what you wanted to achieve by using two VM's
Anthony, http://www.airdesk.co.uk



"Nick" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
>I have set up a Win 2003 STD server hosting 2 VMs in a Virtual Server
> environment. I want incoming http requests to be routed to the
> appropriate IIS on one or the other of these 2 VMs, depending on
> domain name, such that www.name1.com goes to VM #1 and www.name2.com
> goes to VM #2.
>
> I would prefer to accomplish this by way of multiple IP address (DNS
> obviously resolving domain name to proper IP) and letting a hardware
> router send the incoming requests to the proper server, based on the
> IP address. My problem is my current router (a cheapo LinkSys) does
> not handle more than one IP address. I can only do port forwarding,
> and that's not good enough. Can someone recommend a suitable 'small
> business' class router, or perhaps another solution? I've done
> searches and not coming up with much. I'd be grateful. thanks, Nick
>

"Nick" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
>I have set up a Win 2003 STD server hosting 2 VMs in a Virtual Server
> environment. I want incoming http requests to be routed to the
> appropriate IIS on one or the other of these 2 VMs, depending on
> domain name, such that www.name1.com goes to VM #1 and www.name2.com
> goes to VM #2.
>
> I would prefer to accomplish this by way of multiple IP address (DNS
> obviously resolving domain name to proper IP) and letting a hardware
> router send the incoming requests to the proper server, based on the
> IP address. My problem is my current router (a cheapo LinkSys) does
> not handle more than one IP address. I can only do port forwarding,

(bear with me for a moment)
Well there is really no such thing as "port forwarding" if you go with the
literal meaning of the words (which Linksys, DLink, and the others don't
do). The concept of a "Port" is just imaginary. All they are is a Layer4
numerical address to identify the Application that is supposed to receive a
packet. Layer4 addresses are not "routable" and are not "forwardable"
(which "forwarding" means the same thing as "routing" anyway). However they
can be "translated",..as in Port Address Translation (PAT) which can be run
on top of Reverse NAT as I'll describe below.

The *real* term for "port forwarding" is Reverse NAT (or Static Nat). It is
a Layer3 function and focuses on the IP# not the Port#. The problem isn't
that the Linksys "only" does that, because that is all that it needs to do
anyway. The real problem is because the device only allows one IP# to be
bound to the external interface and Reverse NAT (by itself) requires an
external IP# to correspond the the internal IP#. So to get around that you
run PAT over the top of the Reverse NAT. Linksys does not distingush between
Rev-NAT and Rev-NAT with PAT,...they just call the whole thing "port
forwarding" which futher muddies the waters and creates confusion.

[Don't even get me started on what they call "DMZ"]

The way around all this without replacing the box is to use a different
listening port on the Linksys box's external side. With http port 80 is
already assumed, but if a different port is used the user has to include it
in the URL (http://www.somesite.com:8080/index.htm) would target port 8080
instead of 80.

So if you have one web server on 192.168.0.5 and another on 192.168.0.8 you
would setup the Linksys to do this:

Incomming on Sent to
80: 100.200.200.240 80:192.180.0.5 (Rev-NAT)
8080: 100.200.200.240 80:192.180.0.8 (Rev-NAT with PAT)

And there you have,.... "Reverse NAT with Port Address Translation". But if
the port#s don't change then it is just straight "Reverse NAT"

Another approach is to run all the Sites on one webserver with a single/same
ip# and port# and then use Host Headers (a function of IIS) to distiguish
the sites from each other. This way a single IP#/Port# combination works
arcoss the board for everything.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
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