LDAP server: ldap://IP_of_AD_server (I have tried ldaps:// as well)
Port number: 389 (tried 636 with ldaps://)
LDAP version LDAPv3Select true if referrals must be followed (use false for ActiveDirectory): Off
Enable Start-TLS: Off
Select how to perform authentication: Search and bind
Attribute to compare to the given login cab uid, cn, mail, … : sAMAccountNameBase
DN for the user search operation. Multiple bases may be separated by a semicolon (: ou=name of,dc=domain,dc=ac,dc=cy (of course using correct OU name and Domain)
Optional extra LDAP filter to be ANDed to the basic (searchuserattribute=username) filter: (&objectClass=user)(sAMAccountName={username}))
Optional DN of the LDAP account used to search for the end-user's DN. An anonymous bind is performed if empty: CN=properuseraccount,OU=User Account,DC=domain,DC=ac,DC=cy (using a proper account and domain)
LDAP attribute of email address: mail
LDAP attribute of full name: displayName (I have used cn as well)
Check to make default authentication method: unticked (I have tried both tick and unticked)
Automatically create user if it exists in LDAP server: unticked (I have tried both tick and unticked)
Grant survey creation permission to automatically created users: unticked
Optional base DN for group restriction: empty
Optional filter for group restriction: empty
Allow initial user to login via LDAP: unticked (I have tried both tick and unticked)

<?php
$ldap_host = "ldap://ldap.server.IP.address";
$ldap_port = 389;
$bind_dn   = "CN=bind_user,OU=User Account,DC=domain,DC=com";
$bind_pwd  = "bind_user_password";
$base_dn   = "ou=actual ou,dc=domain,dc=com";
$username  = "username of actual user on AD";        // sAMAccountName of a real AD user
 
$filter = "(&amp;;(objectClass=user)(sAMAccountName=$username))";
 
$ds = ldap_connect($ldap_host, $ldap_port);
ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($ds, LDAP_OPT_REFERRALS, 0);
 
if (!$ds) {
    die("Could not connect to LDAP server");
}
 
echo "Connected to LDAP<br>";
 
if (!ldap_bind($ds, $bind_dn, $bind_pwd)) {
    die("LDAP bind failed<br>");
}
 
echo "Bind successful<br>";
 
$search = ldap_search($ds, $base_dn, $filter);
$entries = ldap_get_entries($ds, $search);
 
if ($entries["count"] == 0) {
    die("User not found in LDAP<br>");
}
 
$user_dn = $entries[0]["dn"];
 
echo "Found user: $user_dn<br>";
 
// Now try binding as the actual user
$user_password = "password_for_test_user"; // AD password
if (@ldap_bind($ds, $user_dn, $user_password)) {
    echo "<strong>LDAP login successful for user $username</strong>";
} else {
    echo "<strong>LDAP login failed for user $username</strong>";
}
?>

system.db.CDbCommand.query(SHOW FULL COLUMNS FROM lime_surveys)    1    0.00288    0.00288    0.00288    0.00288
system.db.CDbCommand.query(SHOW FULL COLUMNS FROM lime_plugins)    1    0.00106    0.00106    0.00106    0.00106
system.db.CDbCommand.query(SHOW FULL COLUMNS FROM lime_plugin_settings)    1    0.00100    0.00100    0.00100    0.00100
system.db.CDbCommand.query(SHOW FULL COLUMNS FROM lime_settings_global)    1    0.00098    0.00098    0.00098    0.00098
system.db.CDbCommand.query(SHOW FULL COLUMNS FROM lime_asset_version)    1    0.00094    0.00094    0.00094    0.00094
system.db.CDbCommand.query(SHOW CREATE TABLE lime_surveys)    1    0.00064    0.00064    0.00064    0.00064
system.db.CDbCommand.query(SHOW CREATE TABLE lime_plugins)    1    0.00049    0.00049    0.00049    0.00049
system.db.CDbCommand.query(SELECT * FROM lime_asset_version t WHERE path = :path LIMIT 1. Bound with :path='/var/www/html/limesurvey/application/extensions/yiiwheels/widgets/select2/assets')    1    0.00046    0.00046    0.00046    0.00046
system.db.CDbCommand.query(SELECT t1.message AS message, t2.translation AS translation FROM lime_source_message t1, lime_message t2 WHERE t1.id=t2.id AND t1.category=:category AND t2.language=:language. Bound with :category='', :language='en')    1    0.00045    0.00045    0.00045    0.00045
system.db.CDbCommand.query(SELECT * FROM lime_plugins t WHERE t.active=:yp0 ORDER BY priority DESC. Bound with :yp0=1)    1    0.00045    0.00045    0.00045    0.00045
system.db.CDbCommand.query(SELECT * FROM lime_settings_global t WHERE stg_name=:name LIMIT 1. Bound with :name='DBVersion')    1    0.00044    0.00044    0.00044    0.00044
system.db.CDbCommand.query(SHOW CREATE TABLE lime_asset_version)    1    0.00044    0.00044    0.00044    0.00044
system.db.CDbCommand.query(SHOW CREATE TABLE lime_plugin_settings)    1    0.00042    0.00042    0.00042    0.00042
system.db.CDbCommand.query(SELECT * FROM lime_asset_version t WHERE path = :path LIMIT 1. Bound with :path='/var/www/html/limesurvey/application/extensions/FlashMessage/assets')    1    0.00039    0.00039    0.00039    0.00039
system.db.CDbCommand.query(SELECT * FROM lime_settings_global t)    1    0.00038    0.00038    0.00038    0.00038
system.db.CDbCommand.query(SELECT * FROM lime_asset_version t WHERE path = :path LIMIT 1. Bound with :path='/var/www/html/limesurvey/application/extensions/LimeScript/assets/script.js')    1    0.00037    0.00037    0.00037    0.00037
system.db.CDbCommand.query(SHOW CREATE TABLE lime_settings_global)    1    0.00036    0.00036    0.00036    0.00036
system.db.CDbCommand.query(SELECT * FROM lime_plugin_settings t WHERE t.plugin_id=:yp0 AND t.model IS NULL AND t.model_id IS NULL AND t.key=:yp1. Bound with :yp0='5', :yp1='is_default')    1    0.00033    0.00033    0.00033    0.00033