I'm using Wordpress 3.8.1, WPMU Ldap Authentication plugin 4.0.2 (This site fixes the deprecated WordPress functions ), and Linode Hosting with Linux CentOS 6 and I'm still having problems connecting LDAP. When I test the connection it takes a long time and comes back a "Connection: Failed". Is there a way to look at a LDAP Debug file so I can check for errors?
I have my LDAP issues as well. Can you check and see if its not a firewall issue? Usually LDAP directories are behind firewalls and you need to make sure that the connection between your WP and the LDAP directory is open. Also check for if the ldap directory needs to be connected over SSL.