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Why should you try Google Public DNS?
By using Google Public DNS you can:
Frequently Asked Questions
General
Use and support
Technical
Privacy
General
- What is Google Public DNS?
- Google Public DNS is a free, global Domain Name System (DNS) resolution service, that you can use as an alternative to your current DNS provider.
- Why is Google working on a DNS service?
- We believe that a faster and safer DNS infrastructure could significantly improve the web browsing experience. Google Public DNS has made many improvements in the areas of speed, security, and validity of results. We’ve shared these improvements in our documentation, to contribute to an ongoing conversation within the web community.
- Are Googlers using Google Public DNS?
- Yes. We launched Google Public DNS to Googlers a couple of months ago and we have been using it to power our wi-fi networks for visitors as well as our free public wi-fi network in Mountain View.
- Are there any cross-product dependencies with Google Public DNS?
- Google Public DNS is an independent service.
- Do I need a Google Account to use Google Public DNS?
- No.
- How is Google Public DNS different from my ISP’s DNS service or other open DNS resolvers? How can I tell if it is better?
- Open resolvers and your ISP all offer DNS resolution services. We invite you to try Google Public DNS as your primary or secondary DNS resolver along with any other alternate DNS services. There are many things to consider when identifying a DNS resolver that works for you, such as speed, reliability, security, and validity of responses. Unlike Google Public DNS, some ISPs and open resolvers block, filter, or redirect DNS responses.
- How does Google Public DNS handle non-existent domains?
- If you issue a query for a domain name that does not exist, Google Public DNS always returns an NXDOMAIN record, as per the DNS protocol standards. The browser should show this response as a DNS error. If, instead, you receive any response other than an error message (for example, you are redirected to another page), this could be the result of the following:
- A client-side application such as a browser plug-in is displaying an alternate page for a non-existent domain.
- Some ISPs may intercept and replace all NXDOMAIN responses with responses that lead to their own servers. If you are concerned that your ISP is intercepting Google Public DNS requests or responses, you should contact your ISP.
Use and support
- I am using another DNS service now. Can I also use Google Public DNS?
- Yes. You can set Google Public DNS to be your primary or secondary DNS resolver, along with your current DNS resolver. Please remember that operating systems treat DNS resolvers differently: some will only use your primary DNS resolver and use the secondary in case the primary one fails, while others will round-robin among each of the resolvers.
- Is Google Public DNS suitable for all types of Internet-enabled devices?
- Yes. However, in some cases, especially with mobile phones, your experience might not be optimal in terms of speed.
- Can I run Google Public DNS on my office computer?
- Some offices have private networks that allow you to access domains that you can’t access outside of work. Using Google Public DNS might limit your access to these private domains. Please check your IT department’s policy before using Google Public DNS on your office computer.
- In which countries is Google Public DNS available?
- It is available to Internet users around the world, though your experience may vary greatly based on your specific location.
- Does Google Public DNS work with all ISPs?
- Google Public DNS should work with most ISPs, assuming you have access to change your network DNS settings.
- Do I need to use both Google Public DNS IP addresses?
- No. You can use Google as your primary service by just using one of the IP addresses. However, be sure not to specify one address as both primary and secondary servers.
- Does it matter in what order I specify the IP addresses?
- No, the order does not matter. Either IP can be your primary or secondary name server.
- What is the SLA for the service?
- As this is an experimental launch, we are not providing an SLA for this service at this time.
- I’m running an ISP. Can I redirect all my users to Google Public DNS?
- At this time, Google Public DNS is an experimental service without an SLA, intended for individual users. If you do use Google Public DNS, we recommend that you ensure that your users have a backup or failover service.
- How can I get support from the Google Public DNS team?
- We recommend that you join our Google Groups to get useful updates from the team and ask any questions you have. You can also check our Twitter channel for the latest status on Google Public DNS. If you need automated telephone support, see the telephone contact information.
Technical
- Where are your servers currently located?
- Google Public DNS servers are available worldwide.
- How does Google Public DNS know which data center to send me to?
- Google Public DNS uses anycast routing to direct all packets to the closest DNS server. For more information on anycast routing, see the Wikipedia entry.
- Does Google Public DNS support the DNSSEC protocol?
- At this time, Google Public DNS does not validate DNSSEC responses. We will continue to work on improving Google Public DNS.
- Is Google Public DNS based on open source software, such as BIND?
- No. Google Public DNS is Google’s own implementation of the DNS standards.
- Does Google Public DNS comply with the DNS standards set forth by the IETF?
- Yes.
- Are there plans to release Google Public DNS code as open source software?
- At this time, there are no plans to open source Google Public DNS, but we have detailed all the steps we have taken to increase speed, security, and standards compliance.
- Does Google Public DNS support IPv6?
- Google Public DNS can respond to requests for IPv6 addresses (AAAA requests), but it does not yet support native IPv6 transport and cannot talk to IPv6-only authoritative nameservers. Clients should use IPv4 network connections to use Google Public DNS.
- I looked online and it seems that there are a lot of issues with open resolvers such as DDoS attacks, large-scale spoofing etc. Why did you make Google Public DNS an open resolver?
- There are many articles online about some of the threats that open resolvers face. We made a conscious decision to be open and we have taken what we believe to be adequate precautions. See the security benefits page for information on the precautions we have taken to help protect our users from spoofing and cache poisoning, and to mitigate DNS-based DDoS attacks.
Privacy
- What information does Google log when I use the Google Public DNS service?
- Google Public DNS complies with Google’s main privacy policy, which you can view at our Privacy Center. With Google Public DNS, we collect IP address (only temporarily) and ISP and location information (in permanent logs) for the purpose of making our service faster, better and more secure. Specifically, we use this data to conduct debugging, to analyze abuse phenomena and to improve our prefetching feature. After 24 hours, we erase any IP information. For more information, read the Google Public DNS privacy page.
- Is any of the information collected stored with my Google account?
- No.
- Does Google share the information it collects from the Google Public DNS service with anyone else?
- No.
- Is information about my queries to Google Public DNS shared with other Google properties, such as Search, Gmail, ads networks, etc.?
- No.
SOURCE : GOOGLE
Introduction to Google Public DNS
Why Google Public DNS?
As web pages become more complex and include more resources from multiple origin domains, clients need to perform multiple DNS lookups to render a single page. The average Internet user performs hundreds of DNS lookups each day, slowing down his or her browsing experience. As the web continues to grow, greater load is placed on existing DNS infrastructure.
Since Google’s search engine already crawls the web on a daily basis and in the process resolves and caches DNS information, we wanted to leverage our technology to experiment with new ways of addressing some of the existing DNS challenges around performance and security. We are offering the service to the public in the hope of achieving the following aims:
- Provide end users with an alternative to their current DNS service. Google Public DNS takes some new approaches that we believe offer more valid results, increased security, and, in most cases, better performance.
- Help reduce the load on ISPs’ DNS servers. By taking advantage of our global data-center and caching infrastructure, we can directly serve large numbers of user requests without having to query other DNS resolvers.
- Help make the web faster and more secure. We are launching this experimental service to test some new ways to approach DNS-related challenges. We hope to share what we learn with developers of DNS resolvers and the broader web community and get their feedback.
Google Public DNS: what it is and isn’t
Google Public DNS is a recursive DNS resolver, similar to other publicly available services. We think it provides many benefits, including improved security, fast performance, and more valid results. See below for an overview of the technical enhancements we’ve implemented.
Google Public DNS is not, however, any of the following:
- A top-level domain (TLD) name service. Google is not an operator of top-level domain servers (generic or country-code), such as Verisign.
- A DNS hosting or failover service. Google Public DNS is not a third-party DNS application service provider, such as DynDNS, that hosts authoritative records for other domains.
- An authoritative name service. Google Public DNS servers are not authoritative for any domain. Google maintains a set of other nameservers that are authoritative for domains it has registered, hosted at ns[1-4].google.com.
- A malware-blocking service. Google Public DNS does not perform blocking or filtering of any kind.
Overview of benefits and enhancements
Google Public DNS implements a number of security, performance, and compliance improvements. We provide a brief overview of those enhancements below. If you’re a developer or deployer of DNS software, we hope you’ll also read the technical information pages on this site for more information on these features. Ultimately, our hope is to share our insights and inspire the community to adopt some of these features in all DNS resolvers. The changes are grouped into 3 categories:
- Performance. Many DNS service providers are not sufficiently provisioned to be able to support high-volume input/output and caching, and adequately balance load among their servers. In addition to load-balancing user traffic to ensure shared caching, Google Public DNS implements “smart” caching to increase the speed of responses. Google Public DNS independently resolves domain names and keeps the resolutions in the cache until their time-to-live (TTL) expires, at which point they are automatically refreshed. The cycle of caching and refreshing is performed offline, asynchronously with user requests, so that responses are almost always available directly from cache. For more information, see the page on performance benefits.
- Security. DNS is vulnerable to various kinds of spoofing attacks that can “poison” a nameserver’s cache and route its users to malicious sites. The prevalence of DNS exploits means that providers have to frequently apply server updates and patches. In addition, open DNS resolvers are vulnerable to being used to launch denial-of-service (DoS) attacks on other systems. To defend against such attacks, Google has implemented several recommended solutions to help guarantee the authenticity of the responses it receives from other nameservers, and to ensure our servers are not used for launching DoS attacks. These include adding entropy to requests, rate-limiting client traffic, and more. For more information, see the page on security benefits.
- Correct results. Google Public DNS does its best to return the right answer to every query every time, in accordance with the DNS standards. Sometimes, in the case of a query for a mistyped or non-existent domain name, the right answer means no answer, or an error message stating the domain name could not be resolved. Google Public DNS never blocks, filters, or redirects users, unlike some open resolvers and ISPs.
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