DNS Routeing

[adamw]

We have a network setup
we have Server ONE Main Server (Exchange DNS AD SQL 2008 R2 IIS7 Windows Server 2008 R2 OS)
server 2 other server (SQL 2005 IIS6)
all traffic is DMZ into server 1 bc that is where most of the stuff is what i would like to do is route a subdomain ex. portal.mydomain.com to server 2 can this be done with dns

here is how our network works we have a domain from godaddy in godaddy we have all of ur A Records
www.domain
mail.domain
portal.domain
point to our static ip from our ISP

would it work to put a fowarded lookup zone in DNS and have it go to server two or would that work any other ideas to have two port 80 sites in same ip difffernt computers

Thanks

[Twanks]

Do you use Apache as a webserver? You can configure Apache to proxy requests to multiple internal servers. Search "Apache reverse proxy". I can send an example configuration if you would like.

Edit: I did see you are using IIS 7. I'll see what can be done about proxying requests to other internal servers.
Edit: Not familiar with IIS, but maybe this link will help. forums.iis.net/t/1157619.aspx I've done the same thing you are looking to do with Apache, and I believe the term is still the same. "Reverse Proxy"

[EricE]

Originally Posted by adamw

would it work to put a fowarded lookup zone in DNS and have it go to server two or would that work any other ideas to have two port 80 sites in same ip difffernt computers

Your mixing concepts. All DNS does is translate a name to an IP address. Your firewall does the mapping of traffic from your external IP address to your internal IP addresses.

So if you have A records for Server1 and Server2, when someone types in server1.mydomain.com they get the IP address for it and if someone types in server2.mydomain.com they get the IP address for that depending on how you have your A records configured (more on that later)

That's it. DNS speaks whole IP addresses, nothing else. No ports, no internal networks.

For routing traffic that's where your firewall comes into play. If you have a typically Internet connection, you have a firewall with the WAN/Internet side with a single public IP address (presumably static since you are pointing to it via DNS). That cable is in one port on your firewall, usually labeled LAN. You typically have a second cable on your firewall, usually labeled LAN, with all your computers behind the firewall via network address translation (NAT).

Whether you have a DMZ or not is not really relevant if that is your above configuration - DMZ is just another LAN.

Using NAT, as you allude to, you can't have two servers behind one public IP address using the same port (80 in your case). You have two options:

1) Put server two's web services on a port other than 80 (i.e. 8080)
Server1 and Server2 would point to the same IP in your DNS
You would have to add a NAT rule in your firewall to map traffic to your external IP and port 8080 to the internal IP address for Server2
2) Obtain a second static IP address from your ISP
Server1 and Server2 would point to each static IP address (Server2 would point to the new static IP address you obtain, leave Server1 alone)
Create a new NAT rule in your firewall to map the new static IP address and traffic on port 80 to Server2 internal IP address

Hope that helps!