[ale] possibility of running an NTP server

JD jdp at algoloma.com
Wed Jan 11 06:59:09 EST 2012


I didn't read your entire post. Sorry.

You don't run an NTP server already?

Have 1 main internal NTP server that all other systems - including WINDOWS - use.

Just run it at a lower stratum level and do not make it publicly available.
Point all your other systems to that main system. There are lots of how-to
guides on the internet.  It should take less than a minute per system to setup.

NTP has been solved for decades.

On 01/11/2012 12:55 AM, Ron Frazier wrote:
> Hi Guys,
> 
> Hope you had a Merry Christmas and a Happy start to the new year.  While 
> I'll admit that I haven't read all the 200+ messages on the list since 
> vacation, I do have a new question I wanted to ask.  I'll go ahead and 
> give the caveat that this falls into the category of something that I 
> might like to do but may never get around to, or it may be too costly, etc.
> 
> For some time, I've had an amateur interest the science of timekeeping.  
> Haven't really pursued it.  I've been recently been doing research into 
> time servers, and time signals, etc.  I used some Christmas money to get 
> a solar atomic watch made by Casio and a couple of solar atomic wall 
> clocks made by LaCrosse Technology.  They're very cool.  They receive 
> the WWVB time signal from the NIST in Colorado.  They charge themselves, 
> and set themselves.  I never have to set them, and I never have to 
> replace the batteries, at least until the rechargeable batteries in them 
> die, and as long as I give them an adequate dose of light.  The problem 
> with the WWVB signal is that it usually doesn't work in the daytime due 
> to the ionosphere and other interference.  So, I was trying to 
> synchronize my watch and one clock today and they just refused to 
> receive the signal enough to work.  Hopefully, they'll pick it up in the 
> middle of the night.
> 
> In my research, I ran across the NTP Pool project at 
> http://www.pool.ntp.org/en/ .  They and people associated with them 
> operate a pool of 2904 servers for the purpose of providing NTP time 
> service.  They also say, on their site, that they need more servers.  
> So, the thought crossed my mind that I could operate an NTP server and 
> associate with the pool.  That brings up a bunch of questions.
> 
> As I understand it, the time servers / devices are divided into Stratum 
> levels.  Stratum 0 devices are the actual atomic clocks, etc. that run 
> the world's timekeeping systems at the highest level.  Stratum 1 devices 
> are connected to Stratum 0 devices directly, not through the internet.  
> I presume that the computer running the radio transmitter at NIST in 
> Colorado is a Stratum 1 device.  Stratum 2 devices are more numerous and 
> are connected to Stratum 1 devices through the internet.  Stratum 3 
> devices are more numerous and are connected to Stratum 2 devices through 
> the internet.  This is a useful article on Wikipedia: 
> http://en.wikipedia.org/wiki/Network_Time_Protocol .
> 
> This document: http://support.ntp.org/bin/view/Servers/WebHome provides 
> access to a list of time servers.
> 
> This document: http://support.ntp.org/bin/view/Servers/RulesOfEngagement 
> shows the rules for usage of the servers.  It discourages use of Stratum 
> 1 servers except where Stratum 2 servers are the clients and where those 
> servers provide time synchronization to a large number of lower level 
> users.  Thus, I'm presuming that, if I were to operate an NTP server, 
> mine would be considered a Stratum 3 server and mine would primarily 
> reference Stratum 2 servers to get time data.  So, I would set the 
> configuration file on my system to have the NTP daemon reference a 
> number of Stratum 2 servers for time synchronization data.  As I 
> understand it, each network hop adds up to about 150 mS of delay, so I 
> would expect my Stratum 3 server to have it's time delayed about 300 mS 
> from the upline Stratum 1 source.  Since the Stratum 1 servers are 
> connected directly to the atomic clocks, etc, I would expect that the 
> time on the Stratum 1 devices differs very little from the true time.
> 
> According to this page: http://www.pool.ntp.org/en/join.html regarding 
> joining the NTP pool, Stratum 3 or Stratum 4 servers can join the pool.
> 
> Assuming I wanted to set up an NTP server, that brings up yet more 
> questions.  Can I do it on a residential 3 Mbps up / 16 Mbps down 
> connection from Comcast?  Do I really have to have a static IP or can a 
> Dynamic DNS name suffice?
> 
> Assuming the answers to the last two are yes and yes, I'm assuming I 
> would connect the NTP server outside my home hardware firewall / 
> router.  So, could I connect things as follows (assume TCP/IP v4):
> 
> Internet --> Cable Modem --> 4 Port Router (WAN Port)
> 
> The router provides DHCP service to my internal LAN.
> 
> 4 Port Router (Port 1) --> NTP Server - Set this port to reserve the 
> same internal LAN IP for this server every time by MAC address.  Set up 
> a port forwarding rule to forward incoming NTP packets to this IP.
> 4 Port Router (Port 2) --> My normal other internal computers
> 4 Port Router (Wireless) --> My normal other internal computers
> 
> Assuming all this works, the NTP server will essentially be outside the 
> firewall.  So, what do I need to run the server, an old Pentium 1 300 
> MHz laptop, an old 486 laptop, a router with reflashed firmware, Ubuntu, 
> a stand alone NTP utility booting off of a CD?  All I would want this 
> particular device to do is run NTP and be accessible to me on the 
> Internal LAN for maintenance and configuration.
> 
> I know the question is a bit vague, and spread out, but any light you 
> guys can shed on the topic is appreciated.  Even though I might not be 
> able to set up and run a server, I love to learn about these things 
> regardless.
> \


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