How can I use one public IP address for several internal web servers?

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How can I use one public IP address for several internal web servers?

Asked by bpl5000

at 2024-08-13 18:48:20

Point:500 Replies:10 POST_ID:828745USER_ID:11655

Topic:

Microsoft IIS Web Server;;

We have a web server running IIS7 and we have a few websites on that server. My problem is that we have very few public IPs, yet we have several other web servers in our organization (Apache server, appliances, etc.). I thought maybe I could use my web server running IIS7 to redirect to the appropriate web servers. For example:

1. web1 is my server running IIS
2. I have web2.mydomain.com NAT to web1.mydomain.com
3. web1.mydomain.com has a site in IIS7 with web2.mydomain.com as the host file

This part works great, I go to web2.mydomain.com, and it goes to the web2 site I created on web1. I then want to redirect it to the web2 server, which is inside the firewall in the same vlan as web1. If I redirect it to web2.mydomain.com, inside the firewall it might work, but outside it's just going to send it right back to web1, which will send it to web2... infinite loop!

How can I go about doing this? I'm thinking I could redirect it to a port. I could have web1 redirect the site web2.mydomain.com to something like web3.mydomain.com:8000. Would this work? Is there a better way?

Author: bpl5000 replied at 2024-08-14 08:34:26

Hmm... reverse proxy with URL Rewrite and Application Request Routing. I'm not familiar with any of this, but it sounds like what I need to do.

Accepted Solution

Expert: bigbigpig replied at 2024-08-14 06:23:26

500 points EXCELLENT

You'll need additional resources like a load balancer or another IIS server running ARR in reverse proxy. Here's a writeup on setting that up.

http://www.iis.net/learn/extensions/url-rewrite-module/reverse-proxy-with-url-rewrite-v2-and-application-request-routing

Author: bpl5000 replied at 2024-08-14 04:03:19

mnkhawaja, when you talk about IP headers, I assume you are talking about host headers? If that is the case, I'm already using host headers and that allows me to have multiple sites on one web server. The problem is, I need to go from that one web server to other servers. I have several different web servers and appliances (email filter, email archiver, backup system, etc.) all using http/https.

I can setup the sites on my IIS server with host headers and then redirect them, but I don't know a way to do it without using a different port when redirecting.

Author: bpl5000 replied at 2024-08-13 20:07:52

Thanks mnkhawaja! Can you explain in more detail how I can use IP headers to accomplish this?

Let's say the address is web.mydomain.com and the external address is 65.0.0.1. The internal address is 10.0.0.1 for my server running IIS7 and 10.0.0.2 for my server that I want web.mydomain.com to reach. Later, I will want to add web1.mydomain.com and have that go to 10.0.0.3.

So I setup a DNS entry for web.mydomain.com and web2.mydomain.com to point to 65.0.0.1 and NAT it to 10.0.0.1. What next?

Author: bpl5000 replied at 2024-08-13 19:56:52

Yes, my topic is "How can I use one public IP address for several internal web servers?" and no-ip will not accomplish that. No-ip just allows you to use a dynamic ip or allows you to not have to remember your IP. It is something more suited for home use, not enterprise. It does not allow you to have one public IP and use it for several different web servers. I think you're just not understanding the concept.

Expert: Mohammed Khawaja replied at 2024-08-13 19:46:02

Well there are three ways of doing this:

1. Use multiple IP addresses
2. Forward to different port
3. Use IP headers (my recommendation)

With option 3, you configure your IIS site to use header (i.e. web2.domain.com, web1.mydomain.com, etc.) and they are all bound to same IP. When the request comes in, IIS will check for the header address and will forward it to the appropriate site.