Re:AWS and their billions in IPv4 addresses
by jlgaddis on Tuesday October 20, 2020 @06:20PM
(#24842913)
> Easy, just declare that the entire IPv4 address space is ::x.x.x.x in IPv6 and Bob’s your uncle. No idea why they didn’t do this other than sheer solipsism.
They did [0,1]:
The "IPv4-Compatible IPv6 address" was defined to assist in the IPv6
transition. The format of the "IPv4-Compatible IPv6 address" is as
follows:
| 80 bits | 16 | 32 bits |
+--------------------------------------+--------------------------+
|0000..............................0000|0000| IPv4 address |
+--------------------------------------+----+---------------------+
Note: The IPv4 address used in the "IPv4-Compatible IPv6 address"
must be a globally-unique IPv4 unicast address.
The "IPv4-Compatible IPv6 address" is now deprecated because the
current IPv6 transition mechanisms no longer use these addresses.
New or updated implementations are not required to support this
address type.
[0]: https://tools.ietf.org/html/rfc4291#section-2.5.5.1
[1]: https://en.wikipedia.org/wiki/IPv6#IPv4-mapped_IPv6_addresse...
This sounds like it works but when you get into the details it gets ugly.
HN discussion: https://news.ycombinator.com/item?id=10854570
Easy, just declare that the entire IPv4 address space is ::x.x.x.x in IPv6 and Bob’s your uncle. No idea why they didn’t do this other than sheer solipsism.