In computing, a name server (also called 'nameserver') consists of a program or computer server that implements a name-service protocol. It will normally map (i.e. connect) a human-recognisable identifier of a host (for example, the domain name 'en.wikipedia.org') to its computer-recognisable identifier (such as the Internet Protocol (IP) address 145.97.39.155), and vice versa.

Domain Name System

Internet name servers implement the Domain Name System (DNS) protocol. Name servers also exist on some Microsoft Windows networks where one host can take the role of NetBIOS Master Browser and act as a NBNS server. Small local networks of Windows systems require no central name server, and generally perform name-resolution using broadcasts.

A domain name server is a server that governs the DNS records, such as ARECORD (Host), CNAMES (Aliases), and MX (Mail Exchange) for a domain name.

Primary and secondary nameservers

Every domain name must have a primary nameserver (eg. ns1.domainname.com), and at least one secondary nameserver (ns2.domainname.com etc). This requirement aims to make the domain still reachable even if one nameserver becomes inaccessible.

Authoritative name server

An authoritative name server is a name server that can give an authoritative answer to a DNS query, and not just a cached answer that was given by another name server. All primary and secondary name servers give authoritative answers, as can certain other "shadow" name servers.

See also

• Comparison of DNS server software
• DNS Security Extensions (DNSSEC)
• Lightweight Directory Access Protocol (LDAP)
• nscd, a name-service caching daemon
• Name Service Switch (NSS)
• Network Information Service (NIS)
• resolver, resolv.conf, resolvconf for Unix/Linux
• root nameserver

External links

• DNS Resource Directory
• DNS & BIND Resources

References