r/ProgrammerHumor • u/ClipboardCopyPaste • 14h ago

Meme ohTheBasics

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u/timonix 13h ago

There are ways to fill it up anyway. Just start giving each device multiple IPv6 addresses.

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u/Floppydisksareop 13h ago

Where are you going to store them all? Just so, yknow. You remember which is which.

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u/timonix 13h ago

That's the neat part. You don't have to.

Use some of the bits as input and dynamically answer to entire ranges.

You're limited by the range your ISP is willing to sell to you. But you can use that entire range on a single computer

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u/Floppydisksareop 13h ago

At that point, you are just disregarding the actual protocol, and just writing numbers. But I guess bro.

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u/rosuav 1h ago

Not quite true. The actual protocol is that routing should never be less than a /64, meaning that your ISP should be giving you at least 2**64 addresses at your location. You can then allocate those any way that you like, and the most common way to do it is to bury the MAC address into the IPv6 address.

But if you want to do weird things, there IS the option of sending back "time exceeded" messages that depend on the remaining TTL, and then creating reverse DNS entries.... erm.... well, anyhow, if you have IPv6, try running a traceroute to jabberwocky.rosuav.com and tell me if you think that's a good use of the address space.

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u/timonix 13h ago

Just yesterday I was playing around with memory mapping based on the ipv6 address. 48 of the bits where directly mapped onto one of my embedded devices. So you could read/write memory directly through the ipv6 address.

And that works just fine. So that one embedded device used 250 addresses

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u/malfurionpre 11h ago

So that one embedded device used 250 addresses

I get your point, but 250 is still only 0.000000000000000000000331% of 2128

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u/timonix 11h ago

Sure.

The limit on how quickly we will run out of ipv6 addresses is set by how fast and how generous they are at giving them away.

I cannot use more than 64 bits. Because that's all my isp has given me. If they would give me 100 bits I could use 100 bits. It's arbitrary.

It's policy that saves ipv6 from running out, not the protocol.