Which IPv6 “gratuitious” features (i.e. anything other than the decision to make a breaking change to address formats and accordingly require adapters) would you argue made adoption more difficult?

IPv6 gets a lot of hate for all the bells and whistles, but on closer examination, the only one that really matters is always “it’s a second network and needs me to touch all my hosts and networking stack”.

Don’t like SLAAC? Don’t use it! Want to keep using DHCP instead? Use DHCPv6! Love manual address configuration? Go right ahead! It even makes the addresses much shorter. None of that stuff is essential to IPv6.

In fact, in my view TFA makes a very poor case for a counterfactual IPv4+ world. The only thing it really simplifies is address space assignment.

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avidiax an hour ago | parent | next [-]

It's not that they loaded it up with features, it's that elegance was prized over practicality.

Simplifying address space assignment is a huge deal. IPv4+ allows the leaves of the network to adopt IPv4+ when it makes sense for them. They don't lose any investment in IPv4 address space, they don't have to upgrade to all IPv6 supporting hardware, there's no parallel configuration. You just support IPv4 on the terminals that want or need it, and on the network hardware when you upgrade. It's basically better NAT that eventually disappears and just becomes "routing".

	▲	lxgr an hour ago \| parent [-]
		> They don't lose any investment in IPv4 address space What investment? IP addresses used to be free until we started running out, and I don't think anything of value would be lost for humanity as a whole if they became non-scarce again. > they don't have to upgrade to all IPv6 supporting hardware But they do, unless you're fine with maintaining an implicitly hierarchical network (or really two) forever. > It's basically better NAT How is it better? It also still requires NAT for every 4x host trying to reach a 4 only one, so it's exactly NAT. > that eventually disappears Driven by what mechanism?

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iso1631 an hour ago | parent | prev [-]

Having both a real address, a link-local address, and a unique local address, and the requirement to use the right one in each circumstance

The removal of arp and removal of broadcast, the enforcement of multicast

The almost-required removal of NAT and the quasi-relgious dislike from many network people. Instead of simply src-natting your traffic behind ISP1 or ISP2, you are supposed to have multiple public IPs and somehow make your end devices choose the best routing rather than your router.

All of these were choices made in addition to simply expanding the address scope.

	▲	lxgr an hour ago \| parent [-]
		> Having both a real address, a link-local address, and a unique local address, and the requirement to use the right one in each circumstance Only use the real one then (unless you happen to be implementing ND or something)! > The removal of arp and removal of broadcast, the enforcement of multicast ARP was effectively only replaced by ND, no? Maybe there are many disadvantages I'm not familiar with, but is there a fundamental problem with it? > The almost-required removal of NAT Don't like that part? Don't use it, and do use NAT66. It works great, I use it sometimes!