编辑“︁Google Public DNS”︁

{{Expand language|1=en|time=2025-10-21T14:27:32+00:00}}
{{noteTA|G1=IT}}
{{Infobox Software | name = {{lang|en|Google Public DNS}}
| developer = [[Google]]
| latest_release_version =
| latest_release_date = 2009年12月5日
| latest_preview_version =
| latest_preview_date =
| operating_system =
| genre = [[域名解析]]
| license =
| website = {{URL|https://developers.google.com/speed/public-dns/}}
}}

'''{{lang|en|Google Public DNS}}'''是[[Google]]自2009年12月5日起提供的一个免费的域名解析服务（[[DNS]]）。Google表示推出此服务主要是为改进网络浏览速度和用户浏览体验。Google为此不使用[[BIND]]等廣為使用的DNS程式，而是以自行開發的軟體对DNS服务器技术进行改进，在兩層[[計算機叢集]]上，[[缓存]]DNS服务器[[負載均衡 (計算機)|平衡負載]]以提升性能，同时保证DNS服务的安全性和准确性<ref>{{cite web | url=https://developers.google.com/speed/public-dns/docs/performance | title=Performance Benefits - Public DNS — Google Developers | date=2012-04-19 | accessdate=2012-12-25 | archive-date=2020-12-07 | archive-url=https://web.archive.org/web/20201207090700/https://developers.google.com/speed/public-dns/docs/performance | dead-url=no }}</ref><ref name=introduction>{{cite web|url=https://developers.google.com/speed/public-dns/|title=Introduction to Google Public DNS|date=2011-02-06|accessdate=2012-04-23|archive-date=2020-12-18|archive-url=https://web.archive.org/web/20201218191817/https://developers.google.com/speed/public-dns|dead-url=no}}</ref>。

== 服务 ==
此服务的地址如下：
;[[IPv4]]位址
* '''<code>8.8.8.8</code>''' (<code>google-public-dns-a.google.com</code>)
* '''<code>8.8.4.4</code>''' (<code>google-public-dns-b.google.com</code>)

;[[IPv6]]位址 <ref>{{Cite web |url=https://developers.google.com/speed/public-dns/docs/using |title=Get Started {{!}} Public DNS {{!}} Google Developers |accessdate=2016-07-27 |archive-date=2012-04-17 |archive-url=https://web.archive.org/web/20120417213538/https://developers.google.com/speed/public-dns/docs/using |dead-url=no }}</ref>
* '''<code>2001:4860:4860::8888</code>'''
* '''<code>2001:4860:4860::8844</code>'''

;[[DNS]]位址
*'''<code>dns.google</code>

该服务不使用[[BIND]]等第三方[[DNS管理软件]]，而是以自行开发的软件实现，并提供有限的IPv6支持，依照[[IETF]]提供的DNS服务标准设计，同时部分支持[[DNSSEC]]协议。<ref>{{cite web|url=//code.google.com/intl/en-EN/speed/public-dns/faq.html|accessdate=2009-12-04|title=Frequently Asked Questions|deadurl=yes|archiveurl=https://web.archive.org/web/20100206180744/http://code.google.com/intl/en-EN/speed/public-dns/faq.html|archivedate=2010-02-06}}</ref>

许多主要DNS提供商处理查询<!--processing queries-->时实施[[域名劫持]]，导致浏览器进入未注册域名时被重定向到广告提供商的页面，此举明显破坏DNS规范。<ref>{{cite web |url=http://www.aczoom.com/blog/2010-01-06/public-dns-server-with-no-hijacking |title=Public DNS Server with no hijacking! |accessdate=2012-06-22 |archive-date=2016-05-12 |archive-url=https://web.archive.org/web/20160512185038/http://www.aczoom.com/blog/2010-01-06/public-dns-server-with-no-hijacking |dead-url=no }}</ref>如中国电信在此情况下可能弹出充满广告的114页面，<ref name=114advertisement>{{cite web|url=http://search.gd118114.cn/|title=中国电信DNS纠错页|date=2011-02-07|access-date=2011-02-07|archive-date=2014-09-09|archive-url=https://web.archive.org/web/20140909145656/http://search.gd118114.cn/|dead-url=yes}}提示信息：“尊敬的用户：您访问的域名不存在，您可尝试重新访问!”</ref>又如[[OpenDNS]]会显示一个有广告或搜索引擎的域名解析错误提示页面。<ref name=opendnsmakemoney>{{cite web|url=http://www.opendns.com/support/#how_does_opendns_make_money|title=How Does OpenDNS Make Money|date=2011-02-07|accessdate=2011-02-07|archive-date=2021-01-26|archive-url=https://web.archive.org/web/20210126153913/https://www.opendns.com/support/#how_does_opendns_make_money|dead-url=no}}</ref>相比而言，Google的此服务会正确回复NXDOMAIN。<ref>{{cite web |url=http://www.webmasterworld.com/goog/4036335.htm |title=Google Launches Public DNS |accessdate=2012-06-22 |archive-date=2018-06-24 |archive-url=https://web.archive.org/web/20180624093131/https://www.webmasterworld.com/goog/4036335.htm |dead-url=no }}</ref>

在第三方服务商以合法途径用DNS服务尝试将用户重定向至恶意网站的情况下，Google还特别重视处理域名服务的安全问题。他们证实其成果可抵御[[域名服务器缓存污染]]以及[[分布式拒绝服务攻击]]。<ref>{{cite web |url=https://developers.google.com/speed/public-dns/docs/security |title=Google Public DNS Security Threats and Mitigations |accessdate=2012-06-22 |archive-date=2020-12-09 |archive-url=https://web.archive.org/web/20201209005249/https://developers.google.com/speed/public-dns/docs/security |dead-url=no }}</ref>

Google称该服务有多种性能和速度上的优势，<ref>{{cite web |url=https://developers.google.com/speed/public-dns/docs/performance |title=Google Public DNS Performance Benefits |accessdate=2012-06-22 |archive-date=2020-12-07 |archive-url=https://web.archive.org/web/20201207090700/https://developers.google.com/speed/public-dns/docs/performance |dead-url=no }}</ref>诸如使用[[任播]]路由<!--anycast routing-->将用户导流到最近的全球数据中心，为服务器预留空间到句柄即使遭遇恶意通路{{what}}，以及使用两个缓冲层以保证服务器负载平衡，使用小型单机[[缓存]]吸纳多数常用域名及其他按域名区分的设备缓冲池以锁定{{what}}。第二层缓存可降低能造成服务器增多的破损缓存失败的几率{{what}}。

==隐私==
Google称为了性能及安全，服务器仅留存用户的[[IP地址]]（24小时后删除）、[[互联网服务提供商|ISP]]和地理位置信息（永久保存）。<ref>{{cite web |url=//code.google.com/intl/en-EN/speed/public-dns/faq.html#privacy |title=Public DNS Privacy FAQ |publisher=Code.google.com |date=2012-10-05 |accessdate=2012-10-10 |deadurl=yes |archiveurl=https://web.archive.org/web/20100206180744/http://code.google.com/intl/en-EN/speed/public-dns/faq.html#privacy |archivedate=2010-02-06 }}</ref><ref>{{cite web |url=//www.google.com/privacypolicy.html |title=Google Privacy Policy |publisher=Google.com |date=2012-07-27 |accessdate=2012-10-10 |archive-date=2010-12-02 |archive-url=https://web.archive.org/web/20101202041652/http://www.google.com/privacypolicy.html |dead-url=no }}</ref><ref>[http://www.pcworld.com/article/183671/google_public_dns_and_your_privacy.html Google Public DNS and your privacy] {{Wayback|url=http://www.pcworld.com/article/183671/google_public_dns_and_your_privacy.html |date=20150519055810 }} PC World, 4 December 2009</ref>

==历史==
2009年12月，Google产品经理Prem Ramaswami在官方博客中宣布启动Google Public DNS<ref>[http://googleblog.blogspot.com/2009/12/introducing-google-public-dns.html Introducing Google Public DNS] {{Wayback|url=http://googleblog.blogspot.com/2009/12/introducing-google-public-dns.html |date=20190221001213 }} Official Google Blog, 3 December 2009</ref>，并同时在[[Google Code]]发布此消息。<ref>{{cite web |url=http://googlecode.blogspot.com/2009/12/introducing-google-public-dns-new-dns.html |title=Introducing Google Public DNS |publisher=Google Code Blog |date=2009-12-03 |accessdate=2014-01-21 |archive-date=2019-04-07 |archive-url=https://web.archive.org/web/20190407221602/http://googlecode.blogspot.com/2009/12/introducing-google-public-dns-new-dns.html |dead-url=no }}</ref>

=== 中国大陆的封锁 ===
Google Public DNS曾在2010年9月17日遭到[[防火长城]]的IP地址屏蔽，因而无法从[[中国大陆]]境内正常访问。<ref name=bebanned>{{cite web|url=http://markmail.org/message/ihhyp6cxx3772jro|title=原来Google Public DNS被墙了啊|date=2010-09-17|accessdate=2011-02-06|archive-date=2015-02-27|archive-url=https://web.archive.org/web/20150227084051/http://markmail.org/message/ihhyp6cxx3772jro|dead-url=no}}</ref>现在封锁已经解除，在中国大陆境内也能正常访问和解析绝大部分域名，但由于Google Public DNS的服务器并不在中国境内，故在中国大陆境内所有使用其进行域名解析的请求都会经过防火长城的过滤，从而易被防火长城所干扰，致使在中国大陆境内的客户端不一定能获得正确的解析结果。<ref name=gfwrev-DNS>{{cite web|url=http://gfwrev.blogspot.com/2009/11/gfwdns.html|title=深入了解GFW：DNS污染|date=2009-11-27|accessdate=2011-02-06|archive-date=2020-12-14|archive-url=https://web.archive.org/web/20201214234930/http://gfwrev.blogspot.com/2009/11/gfwdns.html|dead-url=no}}</ref>

自2015年起，原有的干扰手段疑似更换为随机丢包，依靠大量丢包导致Google Public DNS使用体验严重不佳迫使用户更换其他DNS。{{来源请求}}

===DNSSEC===
2013年5月6日，Google Public DNS默认启用[[DNSSEC]]验证，意味着即使客户端未启用，所有的域名解析请求都将接受验证<!-- explicitly opt out -->。<ref>{{cite web |url=http://googleonlinesecurity.blogspot.com/2013/03/google-public-dns-now-supports-dnssec.html |title=Google Public DNS Now Supports DNSSEC Validation |publisher=Google Code Blog |date=2013-06-01 |accessdate=2014-01-21 |archive-date=2016-02-10 |archive-url=https://web.archive.org/web/20160210112938/https://googleonlinesecurity.blogspot.com/2013/03/google-public-dns-now-supports-dnssec.html |dead-url=no }}</ref>

Google Public DNS起初不直接支持DNSSEC。即使RRSIG不可被查询，AD flag（Authenticated Data，意味着服务器可以验证所有数据的签名）在最初版本中从未设置过。2013年1月28日这种情况得到改进，当时Google的DNS服务器静默启动DNSSEC验证信息的供应，<ref>{{cite web |url=http://seclists.org/nanog/2013/Jan/690 |title=Google's Public DNS does DNSSEC validation |publisher=nanog mailing list archives |date=2013-01-29 |accessdate=2014-01-21 |archive-date=2018-11-11 |archive-url=https://web.archive.org/web/20181111173654/https://seclists.org/nanog/2013/Jan/690 |dead-url=no }}</ref>但是只有客户端启动DNSSEC OK (DO) flag时生效。<ref name="CircleID">{{cite web |url=http://www.circleid.com/posts/20130717_dns_dnssec_and_googles_public_dns_service/ |first=Geoff |last=Huston |title=DNS, DNSSEC and Google's Public DNS Service |publisher=CircleID |date=2013-07-17 |accessdate=2014-01-21 |archive-date=2018-07-01 |archive-url=https://web.archive.org/web/20180701050320/http://www.circleid.com/posts/20130717_dns_dnssec_and_googles_public_dns_service |dead-url=no }}</ref>这一服务需要的client-side flag在2013年5月6日被替换成默认启用的完整的DNSSEC验证。

== 参考文献 ==

{{Reflist|30em}}

== 外部链接 ==
* [https://developers.google.com/speed/public-dns/ Public DNS | Google Developers] {{Wayback|url=https://developers.google.com/speed/public-dns/ |date=20201218191817 }}

{{Google 公司}}

[[Category:Google]]
[[Category:域名解析服务]]