Why and How to Use Google's Public DNS
Joseph Caudle
on
When people email us asking for help with their DNS configuration, we often point them at DNS lookup tools they can use to diagnose problems, but sometimes we're able to narrow down problems to local or ISP provided resolvers. At that point, we sometimes suggest switching to Google's Public DNS. Here's how you can do that and why you might want to consider it.
Google's Public DNS is fast
Google has their Public DNS service available on a global anycast network which provides all of the benefits of anycast for the queries made to them. For largely the same reasons that authoritative name servers on an anycast network provide a speed boost to your customers, anycast resolvers provide a speed boost to you by allowing your browser to make requests to the nearest name server available.
Additionally, Google has taken many steps to reduce latency in DNS queries, including some interesting measures for resolving cache misses across their infrastructure.
Using Google's Public DNS provides increased security
One of the bigger problems with publicly available resolvers is the possibility that they could be used in Denial of Service and Amplification attacks by making a small query which returns a large response. Google has taken a number of measures to protect against some of the most common attacks and monitors their resolvers carefully to ensure bad actors are not able to misuse their service. In addition to monitoring their servers for bad actors, Google Public Resolvers fully support DNSSEC which allows them to guarantee the responses they are offering are authentic and from authoritative sources.
The right answer to every query
One of the biggest reasons we suggest customers switch to Google's resolvers is that their network is set to use improperly configured resolvers. Providing correct results is one of the key benefits which Google Public DNS provides. It puts priority on returning the right answer to a query. In cases when there is a query for a non-existent or mistyped domain name, users get an NXDOMAIN response, which indicates no known response, to their query.
How to use Google Public DNS
Now that we've investigated why you might want to use Google's Public DNS let's take a look at what you need to do to use it. Configuring your settings will vary based on the operating system and device you are using. You will also likely need administrative control of your computer to change these settings, but you should be able to adjust the DNS settings for your system whereever you would adjust other network settings. Specifically, you should use the following addresses, or even just the IPv4 addresses, as your DNS servers.
Google's Public DNS IP addresses (IPv4) are:
- 8.8.8.8
- 8.8.4.4
Google's Public DNS IPv6 addresses are:
- 2001:4860:4860::8888
- 2001:4860:4860::8844
Hopefully this guide will help you avoid problems with your DNS configuration and provide you with more reliable resolution. Of course, you're always welcome to contact us and we'll be more than happy to help.
Joseph Caudle
Teacher of people and computers. Fond of subtle distinctions.
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