7 ms·
How would it have possibly been backwards compatible? Plenty of routers and ip-aware switches have, in hardware, specified that ips are 32-bits, so anything tha
by goatinaboat 6y ago
How would it have possibly been backwards compatible? Plenty of routers and ip-aware switches have, in hardware, specified that ips are 32-bits, so anything that added more bits would necessarily break existing hardware, and thus not be backwards compatible.
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.
- jlgaddis 6y ago> 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 https://tools.ietf.org/html/rfc4291#section-2.5.5.1 [1]: https://en.wikipedia.org/wiki/IPv6#IPv4-mapped_IPv6_addresses https://en.wikipedia.org/wiki/IPv6#IPv4-mapped_IPv6_addresse...
- wmf 6y agoThis sounds like it works but when you get into the details it gets ugly. http://archive.is/eHvKF http://archive.is/eHvKF HN discussion: https://news.ycombinator.com/item?id=10854570 https://news.ycombinator.com/item?id=10854570