IPv6 Adoption in 2026
netmeister.orgGonna re-post my 2023 comment on IPv6:
>It is gradually becoming acceptable to dismiss IPv6 and suggest searching for a modern, practically minded alternative. Important first step in untangling the mess.
>Naturally opinions vary as to what exactly would constitute modern. Common complaint is the significant mixing of OSI layers, in particular application level concerns like significant baggage of encryption & authentication. And then there's my pet peeve of BSD Sockets API incompatibility which was introduced accidentally.
SMTP will never go IPv6 in my opinion.
IP reputation scoring is feasible with 4.3 billion IPv4 addresses.
That model breaks down when you’re dealing with 340,282,366,920,938,463,463,374,607,431,768,211,456 possible IPv6 addresses.
That's not how SMTP reputation scoring works. Even in IPv4 per-IP reputation stopped being sufficient many years ago because bulk senders churn pools and rotate addresses. Modern systems typically score prefixes, ASNs, DKIM/SPF alignment, TLS and behavior.
I published AAAA records for my MX hostnames a few years ago and so far only gmail.com is sending mails via IPv6, which is disappointing.
Microsoft and Google both have IPv6 addresses published for their MX
You can score subnets instead of individual ips.
Perhaps you mean “prefixes” such as they are assigned by registrars, and announced by routing protocols.
The instructor of my Cisco classes said that the only module that caused students to break down in tears was VLSM.