ldap_bind

<?php

// using ldap bind
$ldaprdn  = 'uname';     // ldap rdn or dn
$ldappass = 'password';  // associated password

// connect to ldap server
$ldapconn = ldap_connect("ldap://ldap.example.com")
    or die("Could not connect to LDAP server.");

if ($ldapconn) {

    // binding to ldap server
    $ldapbind = ldap_bind($ldapconn, $ldaprdn, $ldappass);

    // verify binding
    if ($ldapbind) {
        echo "LDAP bind successful...";
    } else {
        echo "LDAP bind failed...";
    }

}

?>

<?php

//using ldap bind anonymously

// connect to ldap server
$ldapconn = ldap_connect("ldap://ldap.example.com")
    or die("Could not connect to LDAP server.");

if ($ldapconn) {

    // binding anonymously
    $ldapbind = ldap_bind($ldapconn);

    if ($ldapbind) {
        echo "LDAP bind anonymous successful...";
    } else {
        echo "LDAP bind anonymous failed...";
    }

}

?>