title: ldapsearch doesn't return results when using userPrincipleName as filter?
body: <p>I have a running freeipa ldap server that I am using for user management. I need to search for users using userPrincipleName attribute. I can search using uid filter as follows:</p>
  
  <p><code>ldapsearch -H "ldap://ldap.domain.net" -D "uid=badr,cn=users,cn=accounts,dc=domain,dc=net" -w "password" -b "uid=badr,cn=users,cn=accounts,dc=domain,dc=net" "uid=badr"</code></p>
  
  <p>But, when I change the filter to <code>userPrincipleName</code>, it returns nothing.</p>
  
  <p><code>ldapsearch -H "ldap://ldap.domain.net" -D "uid=badr,cn=users,cn=accounts,dc=domain,dc=net" -w "password" -b "uid=badr,cn=users,cn=accounts,dc=domain,dc=net" "userPrincipleName=badr@domain.net"</code></p>
  
  <p>I suspect that something has to be done on ldap server in order for it to work correctly.</p>
  
  <p>Where could the mistake be here?</p>
  
  <p>thanks in advance</p>