The AMS-IX mirror of the K root-server.

A root name server is a DNS server that answers requests for the root namespace domain, and redirects requests for a particular top-level domain (TLD) to that TLD's nameservers. Although any local implementation of DNS can implement its own private root name servers, the term "root name server" is generally used to describe the thirteen well-known root name servers that implement the root namespace domain for the Internet's official global implementation of the Domain Name System. Image File history File links Ams-ix. ... Image File history File links Ams-ix. ... The Amsterdam Internet Exchange (AMS-IX) is an Internet Exchange Point situated in Amsterdam, in the Netherlands. ... It has been suggested that this article be split into multiple articles. ... “TLD” redirects here. ...

All domain names on the Internet can be regarded as ending in a full stop character e.g. "www.example.com.". This final dot is generally implied rather than explicit, as modern DNS software does not actually require that the final dot be included when attempting to translate a domain name to an IP address. The empty string after the final dot is called the root domain, and all other domains (i.e. .com, .org, .net, etc.) are contained within the root domain. The term domain name has multiple related meanings: A name that identifies a computer or computers on the internet. ... A full stop or period (sometimes stop, full point or dot), is the punctuation mark commonly placed at the end of several different types of sentences in English and many other languages. ... The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... In computer programming and formal language theory, (and other branches of mathematics), a string is an ordered sequence of symbols. ... A DNS root zone is the top level of the DNS hierarchy for a given DNS system. ...

When a computer on the Internet wants to resolve a domain name, it works from right to left, asking each name server in turn about the element to its left. The root name servers (which have responsibility for the . domain) know about which servers are responsible for the top-level domains. Each top-level domain (such as .com) has its own set of servers, which in turn delegate to the name servers responsible for individual domain names (such as example.com), which in turn answer queries for IP addresses of subdomains or hosts (such as www).

In practice, most of this information doesn't change very often and gets cached, and necessary DNS lookups to the root nameservers are relatively rare. However, there are many incorrectly configured systems on the Internet that are responsible for the majority of root nameserver lookup traffic. For example, queries with the source address 0.0.0.0 (corresponding to anywhere and everywhere) make it to the root servers.^{[citation needed]} Also, misconfigured desktop computers sometimes try to update the root server records for the TLDs, which is incorrect.^{[citation needed]}

There are currently 13 root name servers specified, with names in the form letter.root-servers.net, where letter ranges from A to M. (Seven of these are not actual single servers, but represent several physical servers each in multiple geographical locations; cf. below.):

Approximate geographical location of all DNS root name servers (as of March 2007)

Older servers had their own name before the policy of using similar names was established. VeriSign, Inc. ... Dulles is an unincorporated area in Loudoun County, Virginia. ... BIND (Berkeley Internet Name Domain, previously: Berkeley Internet Name Daemon) is the most commonly used DNS server on the Internet, especially on Unix-like systems, where it is a de facto standard. ... The Trojan Shrine, better known as Tommy Trojan located in the center of University of Southern California campus. ... ÂÂThe Information Sciences Institute (ISI) of the University of Southern California is involved in a broad spectrum of information processing research and in the development of advanced computer and communication technologies. ... Marina del Rey Marina del Rey (Spanish for Navy of the King, or Seacoast of the King) is a census-designated place seaside community located in an unincorporated area of Los Angeles County, California. ... Cogent Communications is a multinational IP Internet Service Provider. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... The University of Maryland, College Park (also known as UM, UMD, or UMCP) is a public university located in the city of College Park, in Prince Georges County, Maryland, just outside Washington, D.C., in the United States. ... College Park is a city in Prince Georges County, Maryland, USA, United States. ... This article is about the American space agency. ... For the community near Martinez, California, see Mountain View, Contra Costa County, California. ... In January 2004 the projects, assets and staff of Internet Software Consortium were transferred to a new company, Internet Systems Consortium. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... The Defense Information Systems Agency (DISA, formerly known as the Defense Communications Agency) is a combat support agency of the United States Department of Defense (DoD) responsible for planning, developing, fielding, operating, and supporting command, control, communications, and information systems that serve the needs of the President, the Secretary of... Nickname: Location in the state of Ohio, USA Coordinates: , Country State Counties Franklin, Delaware, and Fairfield Government  - Mayor Michael B. Coleman (D) Area  - City  212. ... Aberdeen Proving Ground is a United States Army facility located at Aberdeen, Maryland (in Harford county). ... In Internet computing, NSD (for name server daemon) is a server program for the Domain Name System. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... VeriSign, Inc. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... The Réseaux IP Européens Network Coordination Centre (RIPE NCC) is the Regional Internet Registry (RIR) for Europe, the Middle East and Central Asia. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... ICANN headquarters ICANN (IPA /aɪkæn/) is the Internet Corporation for Assigned Names and Numbers. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

No more names can be used because of protocol limitations - UDP packet can only carry 512 bytes reliably and a hint file with more than 13 servers would be larger than 512 bytes - but the C, F, I, J, K, L and M servers now exist in multiple locations on different continents, using anycast announcements to provide a decentralized service. As a result most of the physical, rather than nominal, root servers are now outside the United States. User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite. ... Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ...

There are also quite a few alternative namespace systems with their own set of root nameservers that exist in opposition to the mainstream nameservers. The first, AlterNIC, generated a substantial amount of press. See Alternative DNS root for more information. AlterNIC was an alternative DNS root founded by Eugene Kashpureff. ... In addition to the Internets main DNS root (currently consisting of 13 nominal root nameservers working in agreement with ICANN), several organizations operate alternative DNS roots (often referred to as alt roots). ...

Root name servers may also be run locally, on provider or other types of networks, synchronized with the US Department of Commerce delegated root zone file as published by ICANN. Such a server is not an alternative root, but a local implementation of A through M. ICANN headquarters ICANN (IPA /aɪkæn/) is the Internet Corporation for Assigned Names and Numbers. ...

As the root nameservers function as part of the Internet backbone, they have come under attack several times, although none of the attacks have ever been serious enough to severely hamper the performance of the Internet. Each line is drawn between two nodes, representing two IP addresses. ... A denial-of-service attack (also, DoS attack) is an attack on a computer system or network that causes a loss of service to users, typically the loss of network connectivity and services by consuming the bandwidth of the victim network or overloading the computational resources of the victim system. ...

See also

• Anycast
• DNS Backbone DDoS Attacks
• EDNS0 (Extended DNS, version 0)
• Domain name system
• Internet backbone
• Open Root Server Network

Routing Schemes anycast broadcast multicast unicast Anycast is a network addressing and routing scheme whereby data is routed to the nearest or best destination as viewed by the routing topology. ... The DNS Backbone DDoS Attacks have been several significant Internet events in which distributed denial of service attacks (DDoS) have targeted one or more of the thirteen DNS root servers. ... This article or section is in need of attention from an expert on the subject. ... It has been suggested that this article be split into multiple articles. ... Each line is drawn between two nodes, representing two IP addresses. ... Open Root Server Network (ORSN) is a network of root nameservers for the Internet, operating since February 2002. ...

References

• Root Server Technical Operations Association
• Root Servers' Geographical Locations on Google Maps
• DNS Root Server System Advisory Committee
• DNS Root Name Servers Explained For Non-Experts
• DNS Root Name Servers Frequently Asked Questions
• Location of Root servers in Asia-Pacific
• Bogus Queries received at the Root Servers
• ORSN, Open Root Server Network with IPv6 support in europe
• RFC 2826 - IAB Technical Comment on the Unique DNS Root
• RFC 2870 - Root Name Server Operational Requirements
• RFC 4697 - Observed DNS Resolution Misbehavior (from observations on the Root Servers)