Where does this come from, and can I check it?

Every lookup starts at one of thirteen named root servers, each now copied across hundreds of machines. The figure is taken from IANA, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a technology fact?

Yes. It sits on the Technology shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

The domain name system has thirteen root identities

Every lookup starts at one of thirteen named root servers, each now copied across hundreds of machines The root zone is served by thirteen identities, labelled A through M, a limit set by how much data fitted in an early UDP response. Each identity is now replicated in dozens of countries through anycast, so a query reaches whichever copy is nearest. The root servers do not answer most questions themselves; they point a resolver to the servers for the relevant top level domain. It sits in Mondo's technology collection, one of 200 facts that each trace back to the reference below.

Where this comes from

IANA

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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The Domain Name System DNS was created in 1983Paul Mockapetris designed DNS to replace a central text file containing every host address on the internet Undersea cables carry almost all intercontinental trafficAround 99 percent of international data crosses oceans on glass fibre lying on the seabed, not by satellite One mistyped route can take a country offlineNetworks trust each other's routing announcements, so a single wrong entry can redirect or swallow traffic The world ran out of IPv4 addresses in 2011The last five free blocks were handed to regional registries that February, forcing a move to 128-bit addressing The first website went live in 1991Tim Berners-Lee published the world's first web page at CERN to explain the World Wide Web project The first ARPANET message was intended to say LOGINIn 1969 the first message sent over ARPANET crashed after transmitting only the letters L and O

Tags: dns, internet, anycast

The domain name system has thirteen root identities: the short answers

Where does this come from, and can I check it?: Every lookup starts at one of thirteen named root servers, each now copied across hundreds of machines. The figure is taken from IANA, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a technology fact?: Yes. It sits on the Technology shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.