Talk:Network Time Protocol

WikiProject Time assessment rating comment

A basic B as far as WikiProject Time is concerned.

Want to help write or improve articles about Time? Join WikiProject Time or visit the Time Portal for a list of articles that need improving. -- Yamara 19:07, 17 January 2008 (UTC)

What does this mran ?!

"...the amount of time it takes a proton to pass an electron"

How can one use NTP in Javascript ??. —Preceding unsigned comment added by Mac (talk • contribs) 19:24, 10 February 2003

TCP/IP or not?

NTP is a purely UDP/IP protocol, not TCP/IP.
NTP is one of the oldest TCP/IP protocols still in use

Aren't those two lines contradicting? They are both in the article, so they should either be corrected, or explained —Preceding unsigned comment added by 138.251.200.242 (talk • contribs) 11:12, 4 November 2004

That comes from 20040921 edit by 81.242.243.124. I'm wondering if that's a gremlin. He changed "NTP program developed by the OpenBSD project" to "SNTP..." which seems wrong. Someone with better knowledge of protocols should see.--Chealer 14:57, 2004 Dec 3 (UTC)

NTP is a TCP/IP protocol (which doesn't mean it has anything to do with TCP). No such thing as UDP/IP exists.

Yes. the name "TCP/IP" is confusing. -- Naive cynic 13:00, 20 Jun 2005 (UTC)

Link to list of publich ntp servers

Hello,

I just came to this entry because I was searching for a list of public accesable time servers. Something like:

http://ntp.isc.org/bin/view/Servers/WebHome#Finding_A_Time_Server

I don't know if it's legal to deeply link to it on the main article. —Preceding unsigned comment added by 217.235.11.65 (talk • contribs) 18:41, 26 March 2005

32-bit fractional second part

So you multiply the fractional part by 2^-32 then add it to the integer part to get the time in seconds? Ojw 14:43, 30 August 2005 (UTC)

Denial of Service

The University of Wisconsin Madison suffered a denial of service "attack" from flawed NetGear routers using NTP. Seems like something relevant to this article, though the relevance may be more tangental than anything. Perhaps a request for a new article is warranted? I've not done that before...

The history of the NTP DoS at the UW-Madison as told by the source is at http://www.cs.wisc.edu/~plonka/netgear-sntp/ —Preceding unsigned comment added by DavidDouthitt (talk • contribs) 19:03, 8 November 2005

I heard this story repeatedly from the horse's mouth. What happened was that Netgear outsourced the production of their routers to China, and the designs done there were subpar. They all targetted the same time server at UW Madison, and the reply packets were by default blocked by the firewall, causing a retransmission every second. Think about that - millions of routers hitting on the same time server once a second (whoa...). Eventually were pouring in excess of 50 megabits of traffic onto the UW network. Mills called netgear to tell them that they needed to stop production immediately and fix the problem; Netgear's response was that they saw no reason why they should. Mills then adviced UW to take netgear to court, but UW decided to work out a deal instead. →Raul654 00:56, 9 November 2005 (UTC)

This topic is covered in NTP server misuse and abuse. Jaho 02:52, 15 March 2007 (UTC)

Lawsuits

I am surprised no one has mentioned the Law Suits that NTP has on RIM (& in consideration are MS and IBM) —Preceding unsigned comment added by 130.63.241.79 (talk • contribs) 12:41, 24 November 2005

That's because this article is about the Network Time Protocol, not about NTP, Inc. RossPatterson 03:33, 3 April 2006 (UTC)

Significance of port #123?

Dunno if it's worth mentioning in the main article, but in the UK 123 is the phone number for the Speaking clock. Anyone know if there's any connection between the two? mh. 01:34, 18 December 2005 (UTC)

• There's the fact that Greenwich is historically the world's time authority, so choosing port 123 would make a kind of sense. --Rfsmit (talk) 19:04, 7 December 2007 (UTC)

Chrony NTP daemon

Please mention Chrony as well as Ntp and Openntpd. The home page for the project is http://http://chrony.sunsite.dk/

No need to. This article is about the NTP protocol, ntpd and OpenNTPD are the major deamons implementing it. There are dozens NTP clients out there and chrony is just one of them. Jaho 20:01, 15 March 2007 (UTC)

Clarification needed?

In the "NTP Timestamps" section, there is the following quote:

"The 64 bit value for the fraction is enough to resolve the amount of time it takes a photon to pass an electron at the speed of light."

Unless I'm misunderstanding something, isn't there something missing here? What is the initial distance between these two particles (or whatever they are)? If they're billions and billions of light years apart, for example, then I could probably "resolve the amount of time" for one to pass the other using my kitchen clock. Is this an incomplete quote or am I just confused? 65.183.135.166 (talk) 21:20, 28 November 2007 (UTC)

I think he's trying to refer to the amount of time that a photon would take to travel the diameter of an electron. I'm not sure the quote is clear and even if it is I'm not sure anyone really knows how wide an electron is? There is a classic radius O(10^-15)m, perhaps that is what is being referred to? 92.251.70.206 (talk) 06:13, 5 June 2008 (UTC)

(The point seems to be that 64+64 bits is sufficient for any possible timekeeping needs in our universe, in a stronger sense than the prediction that ["nobody will ever need more than X kilobytes of memory"]. 71.139.177.112 (talk) 01:17, 16 February 2009 (UTC)

Another clarification needed

The section also says

"Implementations should disambiguate NTP time using a knowledge of the approximate time from other sources. Since this only requires time accurate to a few decades, this is unlikely to ever be a problem in general use."

I think I see what this means, but I'm not sure. Maybe an example and an explanation of the assumptions would clarify it, as in:

"For example, an operating system version that was released in the early 21st century can safely assume that the system clock should never be set to a time in the 20th century, and can probably assume that it will not still be in use in the 22nd century. In this case, a time built into the operating system would be the other source."

But it could equally well be talking about the DAYTIME protocol, file timestamps, or the computer's hardware clock. Someone who is confident of what is intended should disambiguate it.

--71.139.177.112 (talk) 01:17, 16 February 2009 (UTC)

How is this used with routers

A lot of notes and discussions on the internet about routers and NTP. I can't find any other subject that "NTP" might stand for, so I assume they are referring to this. But how is this protocol significant to router operation?

Illustration misleading

Under Network_Time_Protocol#Clock_strata, the illustration has arrows indication traffic pointing down. This implies that the higher strata servers push time sync data to the lower strata, when in fact it is a pull operation. —Preceding unsigned comment added by Rfsmit (talk • contribs) 18:56, 7 December 2007 (UTC) (edit: Sorry -- adding sig) --Rfsmit (talk) 18:58, 7 December 2007 (UTC)

Am I the only person that thinks those arrows are YELLOW? I was looking at the diagram for a few seconds thinking to myself "what green arrows?" until I realised it must mean the yellow ones. --Lytel (talk) 17:33, 2 June 2009 (UTC)

I looked at the history of the image, turns out it was change to be colour-blind-friendly. I've updated the description on the page... hope that's OK. --Lytel (talk) 17:34, 2 June 2009 (UTC)