Redirect Internal/external ip page

Question

I have an HTML page and can already view it internally and externally through the iis of windows server 2003.

I am inside a network where Windows server2003 is connected and I want to access the external IP inside that same network and I can’t. But if the internal IP works.

I want to know if there is a way to redirect the IP. Knowing if I am internally or externally the network.

Thank you

Answer 1

Confirm that I am correct, basically you provided an HTML page on IIS and can only access the respective by the correct internal IP?

If yes try to verify these probable causes:

• Make sure your port 80 is open in the firewall.
• Make sure your IIS bindings allow you to fulfill requests via external ip.
• Verify that the router (if it is within your reach and the infrastructure is under your care) is allowing access to port 80.
• If you are running this application at home you need to remember that your public IP does not point directly to your computer so you should create a NAT configuration to redirect requests from port 80 to your internal ip.

Answer 2

Use DNS to solve the problem. The name-solving service in addition to providing a friendly name for the application (Ex.: http://meuapp.empresa.com.br) will solve the routing problem by providing clients with the appropriate IP according to the network the machine is on.

A common scenario currently, is the case where you have an external DNS server for your public domain and an internal one for the corporate network (sometimes it is the same domain server - AD).

Then, just add an entry on the external server with the address for the application (Ex.: http://meuapp.empresa.com.br) pointing to the external IP.

With this, all external machines to your network can already access the application by the new address, assuming that your site is published at port 80.

And then, you will need to perform an external DNS Zone transfer with your domain to Internal, so on your internal server, the DNS entry must return the internal network IP to the application in question.

This will cause that for that particular zone, when the machine is on the internal network, the priority over the DNS address is the internal server, so the address returned by the DNS will be the internal address of the server.

When the computer is on the external network, the DNS priority will be the WEB returning the external address.

With this, the machines start to access the application by the friendly name and the DNS takes care of providing the appropriate IP through the priority in the DNS Zone according to the network in which the machine is.

Heed:

• You should check if your vendor for the Domain allows
  zone transfers.

• If you use other applications with external addresses in this domain, make sure redundancy services do not provide different Ips to the site, as your internal DNS will take over the zone and provide the wrong IP.

• A Load Load sometimes makes load distribution based on multiple instances of applications with different ips, check properly.

If you can, test zone transfers at non-commercial times and check all relevant domains and sub-domains.

Zone Transfer: https://technet.microsoft.com/pt-BR/library/cc781340(v=Ws.10). aspx

Alternatively check your settings against Loopback (see: http://help.screenconnect.com/Cannot_access_external_IP_address_from_LAN). But, there are other implications, such as modifying your firewall settings and sometimes, for security, these settings are disabled. This can also require configurations in different locations (multiple firewalls) and with the increase of applications, using a friendly name is better in terms of maintenance and control of the rules.

Users are also usually happier.