Tom Beecher wrote: > 6.1.3 <https://datatracker.ietf.org/doc/html/rfc7454#section-6.1.3>. >> at the time of writing of this document, IPv4 >> prefixes longer than /24 and IPv6 prefixes longer than /48 are >> generally neither announced nor accepted in the Internet That's why, unlike IPv4, IPv6 is hopeless as rfc2374 was abandoned. Masataka Ohta