alt Hacker NewsIn my opinion the redesign of IPv6 was perfectly fine. The IPv6 headers are significantly simpler that those of IPv4 and much easier to process at great speed.
There was only 1 mistake, but it was huge and all backwards compatibility problems come from it. The IPv4 32-bit address space should have been included in the IPv6 address space, instead of having 2 separate address spaces.
IPv6 added very few features, but it mostly removed or simplified the IPv4 features that were useless.
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> The IPv4 32-bit address space should have been included in the IPv6 address space, instead of having 2 separate address spaces.
The entire IPv4 address space is included in the IPv6 address space, in fact it's included multiple times depending on what you want to do with it. There's one copy for representing IPv4 addresses in a dual-stack implementation, another copy for NAT64, a different copy for a different tunneling mechanism, etc.
There are several ways to map the IPv4 address space into the IPv6 address space, going right back to the first IPv6 addressing architecture RFC. Every compatibility protocol added a new one.
IPv6 added IPSEC which was backported to IPv4.
IPv6 tried to add easy renumbering, which did’t work and had to be discarded.
IPv6 added scoped addresses which are halfbaked and limited. Site-scoped addresses never worked and were discarded; link-scoped addresses are mostly used for autoconfiguration.
IPv6 added new autoconfiguration protocols instead of reusing bootp/DHCP.
> The IPv4 32-bit address space should have been included in the IPv6 address space,
That's ... exactly how IPv6 works?
Look at the default prefix table at https://en.wikipedia.org/wiki/IPv6_address#Default_address_s... .
Or did you mean something else? You still need a dual stack configuration though, there's nothing getting around that when you change the address space. Hence "happy eyeballs" and all that.
> The IPv4 32-bit address space should have been included in the IPv6 address space, instead of having 2 separate address spaces.
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> Addresses in this group consist of an 80-bit prefix of zeros, the next 16 bits are ones, and the remaining, least-significant 32 bits contain the IPv4 address. For example, ::ffff:192.0.2.128 represents the IPv4 address 192.0.2.128. A previous format, called "IPv4-compatible IPv6 address", was ::192.0.2.128; however, this method is deprecated.[5]
* https://en.wikipedia.org/wiki/IPv6#IPv4-mapped_IPv6_addresse...
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