ldap_unbind kills the link descriptor. So, if you want to rebind as another user, just bind again; don't unbind. Otherwise, you'll have to open up a new connection.
(PHP 4, PHP 5, PHP 7, PHP 8)
ldap_unbind — Desenlazar de directorio LDAP
$link_identifier): boolDesenlace de directorio LDAP.
Devuelve true en caso de éxito o false en caso de error.
ldap_unbind kills the link descriptor. So, if you want to rebind as another user, just bind again; don't unbind. Otherwise, you'll have to open up a new connection.