They're replacing it with NTPsec: https://www.ntpsec.org/FAQ.html https://www.ntpsec.org/FAQ.html > NTPsec already fully interoperates with NTP Classic. They

They're replacing it with NTPsec: https://www.ntpsec.org/FAQ.html https://www.ntpsec.org/FAQ.html > NTPsec already fully interoperates with NTP Classic. They use the same protocols and the same time adjustment algorithms. User-visible differences are minor, and consist mostly of obsolete code being dropped and a few tools renamed to reduce NTPsec’s footprint in global namespace. It's impossible to greenfield a new network time synchronization protocol at this point, sure, but NTPsec is not that; it's a cleanup and modernization project. That said, they have removed things, from Mode 7 packets (a known DDoS amplification vector) to support for obsolete time sources and computers: https://www.ntpsec.org/removal-plan.html https://www.ntpsec.org/removal-plan.html https://www.kb.cert.org/vuls/id/568372 https://www.kb.cert.org/vuls/id/568372