RFC1305 - Network Time Protocol (Version 3)  
   The current NTP standard. Available here in HTML, PDF, and Postscript formats.
   http://www.faqs.org/rfcs/rfc1305.html

RFC2030 - Simple Network Time Protocol Version 4  
   The current standard for SNTP, a version of the protocol for implementations which do not need all of the features of NTP. Available here in HTML, PDF, and Postscript formats.
   http://www.faqs.org/rfcs/rfc2030.html

Network Time Protocol Version 3  
   Aimed primarily at helping internal BNL.gov users with NTP, this page provides useful setup information for various flavors of Unix.
   http://www.ccd.bnl.gov/xntp/

Network Time Protocol at the University of Michigan  
   A discussion of why and how to set up NTP software. Some information is specific to the Unversity, some is more general.
   http://www.umich.edu/~rsug/services/ntp.html

Secure Network Time Protocol (stime)  
   Information and drafts from the IETF Working Group pursuing authenticated distribution of time information.
   http://www.ietf.org/html.charters/stime-charter.html

Geodsoft How-To: NTP Time Synchronization  
   A tutorial on installing NTP servers on UNIX (OpenBSD and Linux) and Windows to accurately synchronize computer times.
   http://geodsoft.com/howto/timesync/

Network Time Synchronization Project  
   NTP Project page for Dr. Mills, primary NTP researcher for over twenty years. He and his students are working on NTP version 4 to improve robustness and security.
   http://www.eecis.udel.edu/~mills/ntp.html

Home of the Network Time Protocol  
   NTP official reference implementation (for Unix and Unix-like OSes, with ports to Microsoft Windows NT, VMS, real-time OSes like VxWorks and QNX, etc...). Also jumping-off point to the official NTP documentation and FAQ, community documentation tools (tw
   http://www.ntp.org/

O'Reilly Hardening Cisco Routers  
   Sample chapter from the book, showing the cisco-specific methods of configuring your routers to support using NTP time synchronization.
   http://www.oreilly.com/catalog/hardcisco/chapter/ch10.html

LinuxDevCenter.com: Synchronizing Networks with NTP  
   Accurate timekeeping is vital to accurate records, and accurate logs are the mainstay of good system administration. Glenn Graham explains NTP (the Network Time Protocol) and how to put it to work on your network.
   http://www.linuxdevcenter.com/pub/a/linux/2003/01/02/ntp.html

O'Reilly Cisco Cookbook  
   This book gathers hundreds of example router configurations all in one place. In chapter 14, the authors provide information on configuring, running, and debugging NTP on your Cisco router. This link via O'Reilly's Safari network for online publications
   http://safari.oreilly.com/?x=1&mode=toc&sortKey=title&sortOrder=asc&view=&xmlid=0-596-00367-6&g=&catid=&s=1&b=1&f=1&t=1&c=1&u=1&r=&o=1&n=1&d=1&p=1&srchText=#

Flawed Routers Flood University of Wisconsin Internet Time Server  
   Report by Dave Plonka on the massive problems caused on the University of Wisconsin network and time servers, due to misconfiguration of NetGear equipment
   http://www.cs.wisc.edu/~plonka/netgear-sntp/

The NTP FAQ and HOWTO  
   Understanding and using the Network Time Protocol (A first try on a non-technical Mini-HOWTO and FAQ on NTP)
   http://www.ntp.org/ntpfaq/NTP-a-faq.htm

Public NTP Time Server List  
   Community maintained list of Stratum 1 and Stratum 2 NTP time servers, including policies and requirements for use, contact info, etc.... Maintained via the NTP TWiki, by the admins of the respective sites themselves.
   http://twiki.ntp.org/bin/view/Servers/WebHome

NTP Reference Implementation Mailing Lists  
   Variety of mailing lists used to support ntp.org, including the announce list, CVS logs, bugs, and questions (which is gatewayed to the USENET newsgroup comp.protocols.time.ntp).
   http://mailman.ntp.org/mailman/listinfo

Vendor: Sun Blueprints Online: Using NTP to Control and Synchronize System Clocks - Part I: Introduction to NTP  
   This article is the first of a series on the Network Time Protocol (NTP). NTP allows synchronizing clocks on different network nodes, which is critical in today's networked world. This first article provides an overview of why time synchronization is impo [PDF]
   http://www.sun.com/blueprints/0701/NTP.pdf

Vendor: Sun Blueprints Online: Using NTP to Control and Synchronize System Clocks - Part II: Basic NTP Administration and Architecture  
   This is Part 2 of a three-article series that discusses how to use Network Time Protocol (NTP) to synchronize system clocks. This article explains the basics of client and server administration, covering various client/server configurations, as well as au [PDF]
   http://www.sun.com/blueprints/0801/NTPpt2.pdf

Vendor: Sun Blueprints Online: Using NTP to Control and Synchronize System Clocks - Part III: NTP Monitoring and Troubleshooting  
   This article is the third in a series of three articles that discuss using Network Time Protocol (NTP) to synchronize system clocks. The goal of this article is to provide an effective understanding of NTP troubleshooting and monitoring. [PDF]
   http://www.sun.com/blueprints/0901/NTPpt3.pdf

Vendor: Sun Blueprints Online: Using NTP on the Sun Fire 15K/12K Server  
   This article addresses the time skew issues for the Sun Fire 12K/F15K server and explains how the system controllers and domains can be configured as NTP clients to external servers. A sample configuration is also provided. This article is targeted to the [PDF]
   http://www.sun.com/blueprints/0603/817-2979.pdf

pool.ntp.org: The Internet Time Network  
   Information on a collection of public NTP servers provided by users and ISP's placed in a DNS round-robin under pool.ntp.org.
   http://www.pool.ntp.org/

NTP Statistics Gathering and Reporting with MRTG  
   David Taylor's short description of how he uses MRTG (and SNMP) to gather and report statistics for NTP for his servers, including Perl scripts, shell scripts, and mrtg.conf examples
   http://www.david-taylor.myby.co.uk/ntp/NTPandMRTG.txt

Vendor: suse.com: Time Synchronization Through the Network  
   This page helps with configuration of NTP software in the S.u.S.E. Linux distribution.
   http://portal.suse.com/sdb/en/2002/02/xntp.html

Vendor: sco.com: Configuring Network Time Protocol (NTP) service  
   A detailed information page about the guidelines for implementing NTP on Caldera (SCO) Linux
   http://docsrv.sco.com/NET_tcpip/CTOC-ntpN.ntp.html

NTP Community Documentation  
   Even though this is hosted at ntp.org, this is not the official NTP documentation or the official NTP FAQ. This is intended to be the collection point for cookbook configurations, tips, hints, tricks, and other comments from directly from various members
   http://twiki.ntp.org/bin/view/Support/WebHome

Vendor: endruntechnologies.com: Introduction to NTP  
   Four page document that gives a very simple high-level overview of how NTP works and some of the issues to be considered when looking to set up NTP time servers. This company is a vendor of NTP time servers and related hardware. [PDF]
   http://www.endruntechnologies.com/pdf/NTP-Intro.pdf