[ntp:questions] Re: Setting up a synchronization network

Richard B. Gilbert rgilbert88 at comcast.net
Fri Jan 16 12:57:03 UTC 2004


I haven't asked the ISP at work but I'll find out who it is and do so.  
I doubt if I'd be allowed to share with anyone outside the firewall!  
It's a zero budget project so there won't be any hardware bought unless 
it comes out of my pocket.  It's not critically important at work; 
people use the time to clock in and out so it should be accurate within 
a few seconds and, when troubleshooting things involving several 
computers, it's helpful if they are all keeping the same time.  What got 
me started was the discovery that among seven of my Alphaservers the 
extremes were about twenty minutes apart.  Then somebody discovered that 
the time clocks (no connection at the time) were not all keeping the 
same time.

I did ask my ISP (Comcast), at home, about NTP servers.  Their tech 
support promptly gave me a bogus IP address and hung up.   The IP 
address was not reachable and was recorded as belonging to the Internet 
Assigned Numbers Authority (IANA).  Does any one know if Comcast has 
such a server?
It's not terribly important at home; I only have six computers running 
and it's a hobby/self study lab.

Hal Murray wrote:

>In article <7tydneoOcadc2prdRVn-uQ at comcast.com>,
> "Richard B. Gilbert" <rgilbert88 at comcast.net> writes:
>  
>
>>The conventional wisdom seems to be that one should have at least three 
>>servers, none having a time source in common with the others and that 
>>these three should be peers.
>>    
>>
>
>Three servers lets you vote out a malicious bad guy.  If you
>want to do that when one of the good guys is down, then you
>need to start with 4 servers.
>
>  
>
>>Do the arithmetic and we need nine servers at stratum 1 and/or 2.  The 
>>trouble is that there don't seem to be nine such servers available!
>>    
>>
>
>You don't really need that many until you have a pretty big empire
>you need to keep in sync.  How big is your system and/or how important
>is it to keep things in sync and/or how accurate do you need things
>to be?
> 
>Several suggestions...
>
>Check out www.pool.ntg.org
>
>Ask your ISP about their NTP server.  If they say "Huh?" (not
>unlikely) you might try to explain things to them and point out
>that it's a good thing for ISPs to offer a good time server to
>their customers.  (Beware of Windows servers.)
>
>Consider getting a GPS clock and running your own stratum-1
>server.  You can build your own if you are willing to tinker
>or buy a ready-to-go box if you have cash and are short on time.
>
>If you get your own GPS setup, then you have something to offer
>in trade:
>
>  Ask your ISP if any other customers have asked about NTP servers.
>  If any of them have setup their own server, they are probably in the
>  same situation as you and would be happy to find a local box to
>  use as a reference in trade for letting you use their box.
>
>  Ask in groups like this if anybody is local who doesn't have an
>  public open policy will trade with you.
>
>  Ask in local users groups and such.
>
>  
>
>
>
>  
>
>>I don't really need the ultimate in accuracy and reliability but if it's 
>>worth doing, it's worth doing well!
>>    
>>
>
>Google for Z3801A.  (HP GPS box, available surplus from the cell phone
>market.  Tinkering required.)
>
>  
>




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