To enable debugging of Kerberos issues in Web JSP, add the following arguments to the Java Options:
-Dsun.security.krb5.debug=true
-Dsun.security.jgss.debug=true
-Dsun.security.spnego.debug=true
After making this change, restart the application server and there will be debug output in the standard error log of the server - for Tomcat, this is the catalina.out or the stderr.out. KB441262
