How to log failed logins?

[Eric Wedaa]

ALL;

  I'm using IDP 2.4 and I've gone into conf/logging.xml and tried both 

<logger name="edu.vt.middleware.ldap.Authenticator" level="INFO"/> 

and 

<logger name="edu.internet2.middleware.shibboleth.idp.authn" level="INFO"/>

and my failed logins are not showing up in any of the logs/* files

What am I doing wrong?  (I need this for audit, so it's kind of a big deal.)

>>Ericw