[ntp:questions] Synchronizing Linux clients with Windows Server 2003 NTP

Richard B. Gilbert rgilbert88 at comcast.net
Mon Jan 22 18:05:12 UTC 2007


george_joby wrote:

> Hi
> 
> Please see the requested information:
> 
> [root at txnaslload03 etc]# ntpq -pn
>      remote           refid      st t when poll reach   delay   offset
> jitter
> ==============================================================================
>  16.74.32.162    .LOCL.           1 u   98  256  377    0.403  -11.752
>  5.775
> *127.127.1.0     LOCAL(0)        10 l   38   64  377    0.000    0.000
>  0.001
> [root at txnaslload03 etc]# ntpq
> ntpq> as
> 
> ind assID status  conf reach auth condition  last_event cnt
> ===========================================================
>   1 40372  9014   yes   yes  none    reject   reachable  1
>   2 40373  9614   yes   yes  none  sys.peer   reachable  1
> 
> ntpq> rv 40372
> assID=40372 status=9014 reach, conf, 1 event, event_reach,
> srcadr=16.74.32.162, srcport=123, dstadr=16.74.35.185, dstport=123,
> leap=00, stratum=1, precision=-6, rootdelay=0.000,
> rootdispersion=10028.351, refid=LOCL, reach=377, unreach=0, hmode=3,
> pmode=4, hpoll=8, ppoll=8, flash=00 ok, keyid=0, ttl=0, offset=-11.752,
> delay=0.403, dispersion=23.991, jitter=5.775,
> reftime=c95f68b3.04189374  Mon, Jan 22 2007 10:45:39.016,
> org=c95f6cfe.e0000000  Mon, Jan 22 2007 11:03:58.875,
> rec=c95f6cfe.e50bc7b4  Mon, Jan 22 2007 11:03:58.894,
> xmt=c95f6cfe.e4e4ead0  Mon, Jan 22 2007 11:03:58.894,
> filtdelay=     0.59    0.58    0.59    0.42    0.42    0.45    0.42
> 0.40,
> filtoffset=  -19.41  -18.48  -18.53  -15.54   -7.28  -14.65   -5.35
> -11.75,
> filtdisp=     15.63   17.55   19.45   21.39   22.35   23.31   24.28
> 25.27
> 
> Please see the rootdispersion value itz too high. Is it the reason the
> client not synchronising with the server?
> Also see client "reject" the server .. in ntpq as command ...
> 
> I will give some more detail about our requirement. The environment
> will be like this. We have 2-3 Linux box then many Non Stop systems and
> a primary Windows 2003 server console and a backup console .. The Linux
> box will be heavy loaded as all the request will be first coming into
> that then to nonstop systems. So customer dont want to put the nonstop
> or linux box as the server .. and the option is Windows 2003 server ...
> Also we dont want to use any external time .. all these boxes should
> sync up and have same time .. But i could see from all the mails and
> from google that I cant use Windows SNTP as a server ... We are just
> trying to figure out why it is not synching with Linux .. i mean the
> real reason and also trying to contact Microsoft to get a confirmation
> that it will not work. So our customer can think about some third party
> NTP software.
> 
> Can some body help me from the above info why client reject the server
> ... is it coz of the high value in root dispertion or due to some other
> issue ??
> 

The root dispersion is much too high!  Servers are selected based on the 
synchronization distance which is defined as the root dispersion plus 
one half of the round trip delay.  The lowest synchronization distance 
wins.  If the lowest synchronization distance is too high (don't know 
the limits) a client may reject all the servers.

Your two basic problems here are trying to operater without reference to 
UTC and trying to use Windows as a time server.

If your Linux box is too busy to be a time server, get another box!  NTP 
does not require a lot of processing power.  A four or five year old 
desktop PC running Linux or Free BSD should be more than adequate.  For 
that matter, an old 80x86 server that has been retired to a job as a 
doorstop should do the job.

If you absolutely cannot connect to the internet, an $85 Garmin GPS18LVC 
timing receiver will make your server march to the beat of UTC.  If you 
have lots of money, $2k-$3K and up, you can buy a plug-in appliance that 
will act as an NTP server




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