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

Network address translation lets dozens of devices share a single public IPv4 address through port mapping. The figure is taken from IETF, 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.

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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

Home routers hide a whole network behind one address

Network address translation lets dozens of devices share a single public IPv4 address through port mapping A router rewrites the source address and port of each outgoing packet, records the mapping in a table and reverses it when the reply returns. That is how several computers browse at once while the outside world sees one address. The technique was meant as a temporary patch for address scarcity, but it became permanent and now complicates direct connections between machines. It sits in Mondo's technology collection, one of 200 facts that each trace back to the reference below.

Where this comes from

IETF

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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Technology trivia

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Computers set their clocks through a server hierarchyThe Network Time Protocol assigns each time source a stratum number, and each level takes its time from the one above The local network committee is named after a dateThe IEEE group behind Ethernet and Wi-Fi took its number from the month and year of its first meeting 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 Ethernet was invented at Xerox PARC in 1973Robert Metcalfe designed the wired networking system inspired by the Hawaiian ALOHANET radio system 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 A TCP connection opens with three short messagesBoth ends exchange synchronise and acknowledge packets before any data moves, agreeing on starting sequence numbers

Tags: nat, networking, routers

Home routers hide a whole network behind one address: the short answers

Where does this come from, and can I check it?: Network address translation lets dozens of devices share a single public IPv4 address through port mapping. The figure is taken from IETF, 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.