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
sca02.sec.dns.exodus.net	209.1.235.120	336
dns01.exodus.net	209.1.222.244	287
dns02.exodus.net	209.1.222.245	282
dns03.exodus.net	209.1.222.246	258
dns04.exodus.net	209.1.222.247	155
exodus.hipdesign.com	63.236.10.5	88
exodus.ssmnet.net	209.173.236.243	65
ns1.exodusgroup.net	66.180.166.32	57
ns2.exodusgroup.net	66.180.161.32	50
exodus.xpr.com	24.173.166.166	43
exodus.eccentrichosting.net	147.202.23.81	31
ns3.nj.exodus.net	209.67.17.6	27
exodus.cdprojekt.com	217.153.35.133	23
ns2.exodus.ro	69.36.7.238	22
ns1.exodus.ro	82.211.39.133	22
exodus.theworldat.com	209.101.130.4	16
exodus2.theworldat.com	209.101.130.5	16
exodus.icorp.net	204.107.221.30	14
sca03.sec.dns.exodus.net	216.32.126.150	11
exodus.entercomp.com	12.181.16.9	11

Survey Limitations

Our survey, while having an impressive 27,104,978 sites and 14,788,158 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).