Enable kerbos Authentication Problem

Hi,

I am enabling the kerberos authentication but when i am browse the application repeated lo-gins asking enter the again and again blank page display...

process of creating

1.creating host header in 80 port

2.enabling kerberoes in manage web application authentication.

3.add host header name in IIS Bindings.

4.set the SPN for the web application.

Regards,

Nani.