IIS 8- Cannot login to website in IIS using Windows authentication when accessing by ip

Question

Dears,

Kindly note that I have a website deployed on IIS 8 in windows server 2012.

When trying to access the website using the host name, the login popup appears and when entering the windows credential, I can enter to the website successfully,

When trying to access the website using the IP address, the login popup appears and when entering the windows credential I cannot log in, and the pop appears again, trying more it returns the same behavior when canceling the popup it gives me the below error:

HTTP Error 401.1 - Unauthorized,

Please note that the "Anonymous Authentication" is enabled using the IUSR identity, and the Windows Authentication enabled with the NTLM and Negotiate providers and the NTLM is first.

I am trying to fix this issue by edit the registry value BackConnectionHostNames and DisableLoopbackCheck following steps in the below article from Microsoft

https://support.microsoft.com/en-us/help/896861/you-receive-error-401-1-when-you-browse-a-web-site-that-uses-integrate

and still not working

Thank you in advance

Answer 1

Consider the differences between navigating by hostname and navigating by IP to your server. Use command prompt and do a tracert IP vs tracert hostname. The difference is by hostname, it resolves your request through the domain name services (knows who you are and who the server is on the domain). By IP, it skips the domain name services and goes directly to the target computer. The network doesn't need the DNS if you use the actual IP address, as the DNS is used for resolving names into IP addresses.

I believe you can directly put the domain name in your code so it knows where to look without relying on the DNS to automatically authenticate (although I haven't done this). Otherwise, let the domain name services resolve the user automatically by authenticating the requestee (the user) to the host (by name) when using the hostname.

Let me know if that makes sense.