Network Time Protocol Version 4: Protocol and Algorithms Specification
This specification has been revised 8 times since RFC 958 (1985). Each document below formally obsoleted the one before it; the versions still in force are listed first.
Revision timeline
Current version — implement against this
Superseded versions — historical reference only
- RFC 958Network Time Protocol (NTP)ObsoletedSeptember 1985replaced by RFC1059, RFC1119, RFC1305
- RFC 1059Network Time Protocol (version 1) specification and implementationObsoletedJuly 1988replaced by RFC1119, RFC1305
- RFC 1119Network Time Protocol (version 2) specification and implementationObsoletedSeptember 1989historicreplaced by RFC1305
- RFC 1305Network Time Protocol (Version 3) Specification, Implementation and AnalysisObsoletedMarch 1992historicreplaced by RFC5905
- RFC 1361Simple Network Time Protocol (SNTP)ObsoletedAugust 1992informationalreplaced by RFC1769
- RFC 1769Simple Network Time Protocol (SNTP)ObsoletedMarch 1995informationalreplaced by RFC2030, RFC4330
- RFC 2030Simple Network Time Protocol (SNTP) Version 4 for IPv4, IPv6 and OSIObsoletedOctober 1996informationalreplaced by RFC4330
- RFC 4330Simple Network Time Protocol (SNTP) Version 4 for IPv4, IPv6 and OSIObsoletedJanuary 2006informationalreplaced by RFC5905
This lineage is derived automatically from the “obsoletes” relationships recorded in the public RFC Editor index — no editorial judgement is applied to the ordering. The most recent document in the chain is RFC 5905 (June 2010).