This report details the names and locations of all DNS servers on the internet, as well as the number of domains that are serviced by these servers. In this fashion, we can discover

• the number of sites hosted by ISPs
• the number of sites hosted by hosting companies that use an ISP's facilities, but run their own name servers
• the number of sites hosted by specialty DNS service providers
• the organizations that choose to operate their own DNS servers rather than to use those of their ISP/hosting provider.

The survey works by determining each month the authoritative name server for each host (and more accurately, each domain) in our survey. We then count the number of domains hosted on each DNS server.

Search

Curious about the size of a the domain set handled by a particular ISP's name servers? Try searching for the ISP's name server. For example, to find Exodus' name servers, try exodus.

Top 20 by Host Name

The top 20 name servers ranked according to the number of domains handled by each name server, with a name server uniquely identified by its fully qualifed name, are shown below.

Name Server Name	Name Server IP	Domains
dns1.name-services.com	98.124.192.1	375,947
dns2.name-services.com	98.124.197.1	375,943
dns3.name-services.com	98.124.193.1	375,870
dns4.name-services.com	69.64.145.225	375,660
dns5.name-services.com	98.124.196.1	374,282
ns1.dreamhost.com	66.33.206.206	228,972
ns2.dreamhost.com	208.96.10.221	228,929
ns3.dreamhost.com	66.33.216.216	228,872
dns2.technorail.com	62.149.132.2	196,103
dns.technorail.com	62.149.128.2	196,101
ns1.sedoparking.com	212.227.86.6	163,337
ns2.sedoparking.com	217.160.208.235	163,332
ns51.domaincontrol.com	216.69.185.26	149,727
ns52.domaincontrol.com	208.109.255.26	149,001
ns1.bluehost.com	74.220.195.31	137,213
ns2.bluehost.com	69.89.16.4	137,203
ns2.xinnet.cn	121.14.70.5	125,564
ns2.xinnetdns.com	121.14.70.4	125,532
ns2.rackspace.com	65.61.188.4	116,949
ns.rackspace.com	69.20.95.4	116,933

Survey Limitations

Our survey, while having an impressive 49,402,479 sites and 22,020,157 domains in the data set, does not include all web sites and domains. We only include those that we consider active, which, by our definition, means we found the site via a link from somewhere else. Sites not linked by anyone are by definition not included in the survey.

We also actively drop sites out of the survey that fail to respond 3 consecutive months to our HTTP queries. So, while a DNS server might still respond with information for a domain, if there is no active web site that we can reach for the domain in question, then the domain is not included in this survey at all, even if it still has other functioning services (such as email).