 The local resolver is usually a system software which in turn puts the query to a "recursive" resolver, which often is located at the Internet service provider.If the latter server deploys RPZ, and either the queried name or the resulting address are in the blocklist, the response is modified so as to impede access.The RPZ mechanism was developed by the Internet Systems Consortium led by Paul Vixie as a component of the BIND Domain Name Server (DNS).