Root Servers

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
HOSTNAME	        IP ADDRESSES	                OPERATOR
a.root-servers.net	198.41.0.4, 2001:503:ba3e::2:30	Verisign, Inc.
b.root-servers.net	199.9.14.201, 2001:500:200::b	University of Southern California, Information Sciences Institute
c.root-servers.net	192.33.4.12, 2001:500:2::c	Cogent Communications
d.root-servers.net	199.7.91.13, 2001:500:2d::d	University of Maryland
e.root-servers.net	192.203.230.10, 2001:500:a8::e	NASA (Ames Research Center)
f.root-servers.net	192.5.5.241, 2001:500:2f::f	Internet Systems Consortium, Inc.
g.root-servers.net	192.112.36.4, 2001:500:12::d0d	US Department of Defense (NIC)
h.root-servers.net	198.97.190.53, 2001:500:1::53	US Army (Research Lab)
i.root-servers.net	192.36.148.17, 2001:7fe::53	Netnod
j.root-servers.net	192.58.128.30, 2001:503:c27::2:30	Verisign, Inc.
k.root-servers.net	193.0.14.129, 2001:7fd::1	RIPE NCC
l.root-servers.net	199.7.83.42, 2001:500:9f::42	ICANN
m.root-servers.net	202.12.27.33, 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.



More information

The organisations that operate root servers map the locations of the many root server 
instances, and also provide other useful material such as statistics on root server 
utilization.