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by ninkendo
1319 days ago
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Giving a /32 to anyone who wants one without any questions asked is probably a good example of why "aren't we making the same mistake as ipv4?" isn't an entirely meritless question. I mean it's probably crazy to imagine a scenario where we have more than 4 billion "local internet registries" in the universe, but it's not so crazy to imagine a scenario where the ability to ask for a /32 maybe needs to get constrained a little more. In the end, I think the idea of making all subnets /64's may have been a mistake. It's cool that you can put MAC addresses right in the address and thus don't need DHCP any more, but carving out room for 18,446,744,073,709,551,616 devices per broadcast domain is a bit crazy on the face of it. Plus you need all the privacy addresses to hide your MAC address from trackers anyway, which is way more complexity than we really needed. IMO DHCP isn't so bad, it's boring/predictable technology at this point, and I'd be perfectly comfortable with shifting the "provider vs customer" boundary many bits to the right in an address, so that a typical subnet is more like a /104 and ISP's give out /96's, etc. That would give us a lot more headroom than the system we have now where anyone can grab a /32. |
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True, but just imagine the subnets are only 64k hosts, with ipv6's address space as a /80.
My own ipv4 routed network (which is currently routed across 5 continents) is based on a space in the 172.16/12 range comprising 5 /16s. A lot of the subnets I use are chopped down to /27, /28 and /29 (and of course /30 and /31s for links and /32s for loopbacks).
That said it's a bit of a squeeze at the moment.
To implement that in an ipv6 world, I'd make every subnet currently sizing between /29 and /25 into a /64. At most it's 8 subnets per /24 at the moment, so call it 16.
As such every /24 I currently allocate would be a /60.
and I have 1280 of those /24s, so 11 bits, which means I need a /49.
Add some expansion space (which I'm currently looking at) and that seems quite neat as a /48.
That's a fairly big network. At some point in the future I could see justifying a second /48.
My company as a whole certainly has more requirement than that, but we have a /32 allocated (we also have a /16 and /19 in ipv4 land and 2 ASes). That /32 could allocate 65,000 of my continent spanning networks. I think we have about 8, and only a couple are really large. The main one is based on the 10/8 network range, which would probably fit into a single /48, but certainly in a handful of them.
> where anyone can grab a /32.
If the requirement to grab a single /32 is an ability to fill in a form asking for it, we aren't going to be running into any issues any time in the next 100 years.