On Fri, 29 Nov 2019 23:26:04 -0500, Brandon Martin said:
definitely the lagging factor, here. I suspect it's at least partially because high-ratio NAT44 has been the norm for enterprise deployments for some time, and, among those who might otherwise be willing to support first-class dual stack, many enterprise IT folks lack the education to recognize the nuance between public addressing and unfiltered public reachability of a given host. I suspect many of them are already using IPv6 for LAN traffic without even realizing it given Windows' penchant for doing so since Vista.
Judging how long it took to (mostly) stamp out CLASSA/B/C nonsense, we're in for at least a decade of IPv6 firewalls that block all ICMP, plus whatever common IPv6 misconfigurations and misconceptions are out there (I was deploying this stuff literally last century, so I admit not knowing what people are screwing up currently).