PHP: Get all groups from Active Directory

I am trying to just get all the global and local groups from active directory.
I am able to bind to the ldap, but I don't know how to go about getting the groups.
Can someone help?

The following code worked with set variables:

$ldapconn = ldap_connect($ad_host,$ad_port) or die("Could not connect to LDAP server.");	
@ldap_set_option($ldapconn , LDAP_OPT_PROTOCOL_VERSION, 3);
@ldap_set_option($ldapconn , LDAP_OPT_REFERRALS, 0);

// binding to ldap server
$ldapbind = ldap_bind($ldapconn,$userlogin, $password);

Select allOpen in new window

This is where I don't know what filter to use to get the group:

if ($ldapbind)
{
  $baseDN = "dc=test,dc=local";
  $strFilter = "(ou=accounts)";
  $strAttributes = array("Group");

  $group_search = ldap_search($ldapconn,$baseDN,$strFilter,$strAttributes);
}

Select allOpen in new window