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What is a DNS and what does it do? (lemmy.world)
submitted 4 months ago by to c/explainlikeimfive@lemmy.world
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[–] 2 points 4 months ago (4 children)

It may also be worth adding, this is done because computers work in numbers, and do not inderstand what a "lemmy.world" is at all, but they understand "104.26.9.209" just fine.

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  • [–] 5 points 4 months ago* (2 children)

    That's not true though. Your computer understands "lemmy.world" just as much or as little as "104.26.9.209". If it couldn't handle a string of letters, it couldn't ask a nameserver for the corresponding IP address either.

    Explaining why we need IP addresses would include the ISO/OSI layer model, fixed size DEST fields in IP packet headers, subnets, routing techniques, BGP and a lot more.

    I could explain all that but it would take hours even when talking to someone who has a rough understanding of network technology and probably days when talking to a (virtual) 5-year-old. In the end it boils down to "Using numbers is more efficient" not to "Using names is impossible" and that must suffice for an ELI5.

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  • [–] 1 point 4 months ago (1 child)

    104.26.9.209 is a bunch of 8 bit numbers. Lemmy.world is a bunch of translation from ascii to numbers to something meaningful. It directly understand 01101000000110100000100111010001 as on off electrical signals.

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  • [–] 3 points 4 months ago* (last edited 4 months ago)

    And your point is? Yes, everything on a PC is a list of numbers. That alone doesn't make an IP address (four 8-bit numbers / one 32-bit number) inherently more meaningful than the ASCII representation of a domain name (eleven 8-bit numbers in the case of "lemmy.world"). The mapping between a letter and its ASCII code is literally one of the most basic things a computer does.

    The advantage comes from IP addresses having a fixed length, from IPv4 addresses being relatively short overall (IPv6 is 16 bytes which is about the same as many domains) and from prefixes being used for routing so you don't need a directory of every single IP address at every router (roughly analogous to country and area codes in phone numbers). None of that is relevant for understanding DNS and none of it means that computers don't "understand" text.

    Edit to fully illustrate my point: IP addresses could just as well be strings like "de/hetzner/falkenstein12/rack42/server23". That would work. It would take up a lot of memory and be much slower than what we have but it would absolutely be possible to build a version of the internet that uses that instead of opaque numbers. And it would still need DNS on top because nobody wants to remember (or even know) where a website's server is physically located.

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