Using PhpLdapAdmin, how do you disable/lock a user/uid so that it can't be used to login to anything on the network that uses LDAP?
The easiest method would be to just zero the password. You could also add an explicit ACL to deny that user access to the directory (remember, an LDAP authentication triggers a bind call).
You could also add a custom field and update your search filter to only include users where that custom field is correct. I do it this way.