Editing Name server (section)

====Recursive query====
{{See also|Public recursive name server}}
If a name server cannot answer a query because it does not contain an entry for the host in its DNS cache, it may recursively query name servers higher up in the hierarchy.<ref name=":0">{{cite web|url=http://www-01.ibm.com/support/docview.wss?uid=pub1sc23881400|title=Composite Application Manager for Internet Service Monitoring, Reference Guide | publisher = IBM | access-date=15 February 2012}}</ref> This is known as a ''recursive query'' or ''recursive lookup''. A server providing recursive queries is known as a ''recursive name server'' or ''recursive DNS'', sometimes abbreviated as '''recdns'''.<ref>{{Cite web|url=https://fanf.livejournal.com/133020.html|title=Network setup for Cambridge's new DNS servers|language=en|access-date=2018-02-05|quote=The recursive DNS server (aka recdns)}}</ref>

In principle, authoritative name servers suffice for the operation of the Internet. However, with only authoritative name-servers operating, every DNS query must start with recursive queries at the [[DNS root zone|root zone]] of the Domain Name System and each user system must implement resolver software capable of recursive operation.{{clarify|date=May 2016}}