SNTP协议详解：简单网络时间同步协议V4

Network Working Group                                           D. Mills
Request for Comments: 2030                        University of Delaware
Obsoletes: 1769                                             October 1996
Category: Informational


             Simple Network Time Protocol (SNTP) Version 4
                         for IPv4, IPv6 and OSI

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Abstract

   This memorandum describes the Simple Network Time Protocol (SNTP)
   Version 4, which is an adaptation of the Network Time Protocol (NTP)
   used to synchronize computer clocks in the Internet. SNTP can be used
   when the ultimate performance of the full NTP implementation
   described in RFC-1305 is not needed or justified. When operating with
   current and previous NTP and SNTP versions, SNTP Version 4 involves
   no changes to the NTP specification or known implementations, but
   rather a clarification of certain design features of NTP which allow

   operation in a simple, stateless remote-procedure call (RPC) mode
   with accuracy and reliability expectations similar to the UDP/TIME
   protocol described in RFC-868.

   The only significant protocol change in SNTP Version 4 over previous
   versions of NTP and SNTP is a modified header interpretation to
   accommodate Internet Protocol Version 6 (IPv6) [DEE96] and OSI
   [COL94] addressing. However, SNTP Version 4 includes certain optional
   extensions to the basic Version 3 model, including an anycast mode
   and an authentication scheme designed specifically for multicast and
   anycast modes. While the anycast mode extension is described in this
   document, the authentication scheme extension will be described in
   another document to be published later. Until such time that a
   definitive specification is published, these extensions should be
   considered provisional.

   This memorandum obsoletes RFC-1769, which describes SNTP Version 3.
   Its purpose is to correct certain inconsistencies in the previous
   document and to clarify header formats and protocol operations for
   current NTP Version 3 (IPv4) and proposed NTP Version 4 (IPv6 and
   OSI), which are also used for SNTP. A working knowledge of the NTP
   Version 3 specification RFC-1305 is not required for an
   implementation of SNTP.



Mills                        Informational                      [Page 1]

RFC 2030             SNTPv4 for IPv4, IPv6 and OSI          October 1996