Editing DNS root zone (section)

==Initialization of DNS service==
The DNS root zone is served by thirteen root server clusters which are authoritative for queries to the [[top-level domain]]s of the Internet.<ref name=Ars /><ref name=RS>{{cite web|title=Root Servers|url=https://www.iana.org/domains/root/servers|access-date=January 17, 2020|publisher=IANA}}</ref> Thus, every name resolution either starts with a query to a root server or uses information that was once obtained from a root server.

The root servers clusters have the official names ''a.root-servers.net'' to ''m.root-servers.net''.<ref name=RS /> To resolve these names into addresses, a DNS resolver must first find an authoritative server for the ''net'' zone. To avoid this [[circular dependency]], the address of at least one root server must be known for [[Bootstrapping (computing)|bootstrapping]] access to the DNS.  For this purpose, operating systems or DNS servers or resolver software packages typically include a file with all addresses of the DNS root servers. Even if the IP addresses of some root servers change, at least one is needed to retrieve the current list of all name servers. This address file is called ''named.cache'' in the [[BIND]] name server reference implementation. The current official version is distributed by [[ICANN]]'s [[InterNIC]].<ref>{{cite web|url=https://www.internic.net/zones/named.cache|title=named.cache|publisher=InterNIC|date=November 17, 2015|access-date=November 17, 2015}}</ref>

With the address of a single functioning root server, all other DNS information may be discovered recursively, and information about any domain name may be found.