Google Public DNS

Google Public DNS is a Domain Name System (DNS) service offered to Internet users worldwide by Google. It functions as a recursive name server. Google Public DNS was announced on December 3, 2009, in an effort described as "making the web faster and more secure." As of 2018, it is the largest public DNS service in the world, handling over a trillion queries per day. Google Public DNS is not related to Google Cloud DNS, which is a DNS hosting service. The Google Public DNS service operates recursive name servers for public use at the four IP addresses listed below. These addresses are mapped to the nearest operational server by anycast routing. The service does not use conventional DNS name server software, such as BIND, instead relying on a custom-designed implementation, conforming to the DNS standards set forth by the IETF. It fully supports the DNSSEC protocol since 19 March 2013. Previously, Google Public DNS accepted and forwarded DNSSEC-formatted messages but did not perform validation. Some DNS providers practice DNS hijacking while processing queries, redirecting web browsers to an advertisement site operated by the provider when a nonexistent domain name is queried. The Google service correctly replies with a non-existent domain (NXDOMAIN) response. The Google service also addresses DNS security. A common attack vector is to interfere with a DNS service to achieve redirection of web pages from legitimate to malicious servers. Google documents efforts to be resistant to DNS cache poisoning, including “Kaminsky Flaw” attacks as well as denial-of-service attacks. The Google Public DNS64 service operates recursive name servers for public use at the two IP addresses listed below for use with NAT64. Google stated that for the purposes of performance and security, the querying IP address will be deleted after 24–48 hours, but Internet service provider (ISP) and location information are stored permanently on their servers. In December 2009, Google Public DNS was launched with its announcement on the Official Google Blog by product manager Prem Ramaswami, with an additional post on the Google Code blog.