Grr LDAP syntax is fussy.
Equality filter:
attribute=value
So what do you think the Inequality filter would be? attribute!=value? attribute!value? No, and no. We use brackets. No problem right? Right…
attribute!(value)
attribute(!value)
!attribute=value
!(attribute=value)
All nope.
You have to do it using BIMDAS, and then put the whole thing in brackets. Oh and the brackets will cause the equality filter to fail.
CORRECT: (!(attribute=value))
INCORRECT: (attribute=value)
Sigh….