[Samba] Authenticating Apache Against Active Directory

[James]

Hello,

    Using Nagios on Ubuntu 14.04.1 LTS. I'm attempting to authenticate
users against Samba 4.2.1. When I edit 'apache2.conf' with


<Directory />
        Options FollowSymLinks
        AllowOverride None
        Require all granted
        Allow from all
        AuthName "AD authentication"
        AuthBasicProvider ldap
        AuthType Basic
        AuthLDAPGroupAttribute member
        AuthLDAPGroupAttributeIsDN On
        AuthLDAPURL
ldap://dc1.domain.local/172.16.232.29:389/cn=Users,dc=domain?sAMAccountName?sub?(objectClass=*)
        AuthLDAPBindDN cn=apache-connect,cn=Users,domain
        AuthLDAPBindPassword password
        require ldap-group cn=Nagios-Admins,cn=Users,domain


and attempt to restart Apache. I get the following.

root at nagios:~# service apache2 restart
 * Restarting web server
apache2                                                                                                             
[fail]
 * The apache2 configtest failed.
Output of config test was:
AH00526: Syntax error on line 159 of /etc/apache2/apache2.conf:
Unknown Authn provider: ldap
Action 'configtest' failed.
The Apache error log may have more information.

I'm not seeing anything of help in the Apache logs. 

-- 
-James