Neighbor Discovery is basically ARP wearing a trenchcoat. The only people "hurt" by the change are the ones who were parsing the output of the arp command for whatever reason.

IMHO the biggest problem is that IPv6 address autoconfiguration was half-baked. There is no mechanism to inform anybody about which address you have configured for yourself, unlike IPv4's DHCP where a central server knows everyone's address and can do things like update DNS entries and configure security devices. Autoconfiguration also didn't include critical details like "Who provides DNS for the local network?" and "What's the NTP server?". There isn't even any way to authenticate that the Router Advertisement your machine receives is valid, although this problem is shared with DHCP. The committee seems to have put a lot of faith in anycast routing, which has never been a good idea outside of toy networks.

> that IPv6 address autoconfiguration was half-baked.

Indeed. I thought I was being an idiot and just not understanding how this was supposed to work, until I learned that it just doesn't do a lot of important things. So when the day comes that I have to move my network to IPv6, I plan on continuing to use DHCP because I want the omitted functionality.

Of course, I still might be being an idiot and not understanding. Getting a solid picture of how IPv6 is supposed to work is genuinely hard to do with any confidence.

Be aware that DHCP6 doesn't work the same as DHCP. It's really intended for configuring routers, not hosts.

I wasn't aware. That's a real bummer, and a good example of the numerous kinds of gotchas that make this transition much more painful than it would otherwise have to be.

The more I learn about IPv6, the more I dread it.