The authoritative name servers that serve the DNS root zone, commonly known as the “root servers”, are a network of hundreds of servers in many countries around the world. They are configured in the DNS root zone as 13 named authorities, as follows.
List of Root Servers
|a.root-servers.net||18.104.22.168, 2001:503:ba3e::2:30||VeriSign, Inc.|
|b.root-servers.net||22.214.171.124, 2001:500:84::b||University of Southern California (ISI)|
|c.root-servers.net||126.96.36.199, 2001:500:2::c||Cogent Communications|
|d.root-servers.net||188.8.131.52, 2001:500:2d::d||University of Maryland|
|e.root-servers.net||184.108.40.206||NASA (Ames Research Center)|
|f.root-servers.net||220.127.116.11, 2001:500:2f::f||Internet Systems Consortium, Inc.|
|g.root-servers.net||18.104.22.168||US Department of Defence (NIC)|
|h.root-servers.net||22.214.171.124, 2001:500:1::803f:235||US Army (Research Lab)|
|j.root-servers.net||126.96.36.199, 2001:503:c27::2:30||VeriSign, Inc.|
|k.root-servers.net||188.8.131.52, 2001:7fd::1||RIPE NCC|
|m.root-servers.net||184.108.40.206, 2001:dc3::35||WIDE Project|
Configuring the Root Servers
Operators who manage a DNS recursive resolver typically need to configure a “root hints file”. This file contains the names and IP addresses of the root servers, so the software can bootstrap the DNS resolution process. For many pieces of software, this list comes built into the software.
For more information, visit information on root zone and root hints access.
ICANN's Root Server System Advisory Council, which is comprised of the organisations that manage root servers, maintains a website with more information on root server operations. This site tracks the locations of the many root servers, and also provides links to individual operators — some of which provide statistics on root server utilisation.