DNS Doctor: DNS Server Types
We are excited to announce a new blog series for all of our DNS Matters readers: DNS Doctor. Each month we will focus on a report from our UltraTools statistics page, highlighting the stats and how the information may help.
Our first post is about DNS server types. As many of you know, DNS Servers hold the authoritative answers (IP addresses) designating the resource location for the server responsible for delivering services for that domain. This is used by applications, such as Web browsers, to make requests from the domain’s resources on the Internet.
Resolving often requires going through several name servers to find the information you need, there is a definitive name server for each part of a domain. For example, “www.ultratools.com” starts at the Root server to find the nameserver for ‘com,’ which provides the nameserver (IP Address) for ‘ultratools,’ which provides the name server (IP Address) for ‘www’ — together representing the zone for the domain. There are other DNS Servers called “Recursive” or “Caching” name servers, which store the answers (like our example) in their local cache, and provide users that answer until it is no longer valid (as defined by the TTL for the record). At all levels, there are many providers of DNS software and managed services.
It is that last point that led us to include DNS server types in our UltraTools statistics. This particular report represents the types and popularity of authoritative DNS name server (resolver) software being used by the Internet’s top 500 domains to resolve DNS queries. As of our July report, the image below shows the most popular DNS name server types being used.
By using this information, you can see what the top Internet domains are using for DNS, and consider this as you make decisions about your DNS implementation. It is also worth noting that “Not Identified” is a collection of nameserver types whose owners provide a response that is either empty, or a phrase of their choosing. Not identifying your nameserver is a tactic to help obscure what you are using, so this information is not readily available to onlookers who might have malicious intentions. For example, knowing you are using BIND might tell a hacker something that they know how to exploit.
Stay tuned for the next DNS Doctor post, and continue to check the UltraTools Stats page to see how things change month to month.