Kerberos Authentication not working in IE

Question

We enabled Kerberos authentication for our on -premise SharePoint web application.

After enabling kerberos, users are able to access the sites in Chrome without issues.

However in Internet Explorer, they get repeated password prompt screen and end up with a error message saying

"Not authorized HTTP Error 401. The requested resource requires user authentication"

I followed all the troubleshooting steps in this article but still get same error:

https://support.microsoft.com/en-us/help/4551934/kerberos-failures-in-internet-explorer

Answer 1

In IIS site, Disabling "Kernel" in "IIS Authentication" resolved the issue

Answer 2

Check your SPN entries. If your site has an SPN entry, the account used in that SPN entry should be the apppool account used to create your site.

If the accounts do not match, the kerberos ticket does not get decrypt.

https://docs.microsoft.com/en-us/troubleshoot/iis/troubleshoot-kerberos-failures-ie

https://techcommunity.microsoft.com/t5/iis-support-blog/service-principal-name-spn-checklist-for-kerberos-authentication/ba-p/347639

Cheers.