diff --git a/html/includes/authentication/ldap.inc.php b/html/includes/authentication/ldap.inc.php
index c091d4b2d..397ca1983 100644
--- a/html/includes/authentication/ldap.inc.php
+++ b/html/includes/authentication/ldap.inc.php
@@ -1,10 +1,11 @@
 <?php
 
+$ds = @ldap_connect($config['auth_ldap_server'],$config['auth_ldap_port']);
+
 function authenticate($username,$password)
 {
-  global $config;
+  global $config, $ds;
 
-  $ds=@ldap_connect($config['auth_ldap_server'],$config['auth_ldap_port']);
   if ($ds)
   {
     if ($config['auth_ldap_version'])
@@ -61,19 +62,57 @@ function adduser($username, $password, $level, $email = "", $realname = "")
 
 function user_exists($username)
 {
-  return 0; # FIXME to be implemented
+  global $config, $ds;
+
+  $filter = "(" . $config['auth_ldap_prefix'] . $username . ")";
+  $search = ldap_search($ds, trim($config['auth_ldap_suffix'],','), $filter);
+  $entries = ldap_get_entries($ds, $search);
+  if ($entries['count'])
+  {
+    return 1;
+  }
+  
+  return 0;
 }
 
 function get_userlevel($username)
 {
-  # FIXME should come from LDAP
-  return dbFetchCell("SELECT `level` FROM `users` WHERE `username` = ?", array($username));
+  global $config, $ds;
+
+  $userlevel = 0;
+
+  # Find all defined groups $username is in
+  $filter = "(&(|(cn=" . join(")(cn=", array_keys($config['auth_ldap_groups'])) . "))(memberUid=" . $username . "))";
+  $search = ldap_search($ds, $config['auth_ldap_groupbase'], $filter);
+  $entries = ldap_get_entries($ds, $search);
+
+  # Loop the list and find the highest level
+  foreach ($entries as $entry)
+  {
+    $groupname = $entry['cn'][0];
+    if ($config['auth_ldap_groups'][$groupname]['level'] > $userlevel)
+    {
+      $userlevel = $config['auth_ldap_groups'][$groupname]['level'];
+    }
+  }
+  
+  return $userlevel;
 }
 
 function get_userid($username)
 {
-  # FIXME should come from LDAP
-  return dbFetchCell("SELECT `user_id` FROM `users` WHERE `username` = ?", array($username));
+  global $config, $ds;
+
+  $filter = "(" . $config['auth_ldap_prefix'] . $username . ")";
+  $search = ldap_search($ds, trim($config['auth_ldap_suffix'],','), $filter);
+  $entries = ldap_get_entries($ds, $search);
+
+  if ($entries['count'])
+  {
+    return $entries[0]['uidnumber'][0];
+  }
+  
+  return -1;
 }
 
 function deluser($username)
diff --git a/includes/defaults.inc.php b/includes/defaults.inc.php
index bf07a927f..855647753 100644
--- a/includes/defaults.inc.php
+++ b/includes/defaults.inc.php
@@ -310,6 +310,11 @@ $config['auth_ldap_prefix'] = "uid=";
 $config['auth_ldap_suffix'] = ",ou=People,dc=example,dc=com";
 $config['auth_ldap_group']  = "cn=observium,ou=groups,dc=example,dc=com";
 
+$config['auth_ldap_groupbase'] = "ou=group,dc=luciad,dc=com";
+$config['auth_ldap_groups']['admin']['level'] = 10;
+$config['auth_ldap_groups']['pfy']['level'] = 7;
+$config['auth_ldap_groups']['support']['level'] = 1;
+
 ### Hardcoded ASN descriptions
 $config['astext'][65333] = "Cymru Bogon Feed";