[ntp:questions] Offset is always increasing

Brian Utterback brian.utterback at oracle.com
Tue May 21 13:55:40 UTC 2013


In an amazingly counter-intuitive manner, a restrict keyword with just 
an IP address means that the IP address should have no restrictions. It 
is therefore very common to see a line like:

restrict default ignore

Which says to ignore all packets from everywhere, and then to see a 
series of lines like

restrict IP1
restrict IP2
etc.

which removes all restrictions from those hosts.


On 05/21/13 08:46, Mischanko, Edward T wrote:
> Why are you doing this?
>
> restrict 10.2.3.5
>
> This is the server you want your clients to sync to, isn't it?
>
> Regards,
> Ed
>
>> -----Original Message-----
>> From: questions-bounces+edward.mischanko=arcelormittal.com at lists.ntp.org
>> [mailto:questions-
>> bounces+edward.mischanko=arcelormittal.com at lists.ntp.org] On Behalf Of
>> Riccardo Castellani
>> Sent: Tuesday, May 21, 2013 6:58 AM
>> To: questions at lists.ntp.org
>> Subject: [ntp:questions] Offset is always increasing
>>
>> I'm using n. 1 ntp server (XNTPD daemon on HP-UX, called FORCLIENTS,
>>
>> 192.168.1.240) for my clients and I'm obtaining the message
>> "synchronization
>> lost" about every 20 minutes.
>> Source time is another server (MASTER) on my lan
>> which updates its time
>> directly from Internet servers.
>>
>>
>> MASTER is OK
>>
>> FORCLIENTS has a high offset !
>>
>>
>> ntp.conf of FORCLIENTS (192.168.1.240):
>>
>>
>> restrict default ignore
>> server 10.2.3.5
>> driftfile /etc/ntp.drift
>> restrict
>> 127.0.0.1
>> restrict 127.127.1.1
>> restrict 10.2.3.5
>> restrict 192.168.1.240
>>
>> restrict 192.168.0.0 mask 255.255.0.0 nomodify noquery
>> server 127.127.1.1
>> fudge
>> 127.127.1.1 stratum 10 # show poor quality
>>
>>
>>
>> ntp.conf of MASTER (10.2.3.5):
>>
>>
>> restrict default ignore
>> restrict 127.0.0.1
>> restrict 192.168.1.240 mask
>> 255.255.255.255 nomodify
>> restrict ntp1.inrim.it mask 255.255.255.255 nomodify
>> noquery notrap nopeer
>> restrict ntp2.inrim.it mask 255.255.255.255 nomodify
>> noquery notrap nopeer
>> restrict ntp1.fau.de mask 255.255.255.255 nomodify
>> noquery notrap nopeer
>> restrict ntp2.nl.net mask 255.255.255.255 nomodify
>> noquery notrap nopeer
>> restrict 127.127.1.0 mask 255.255.255.255
>> server ntp1.
>> inrim.it
>> server ntp2.inrim.it
>> server ntp1.fau.de
>> server ntp2.nl.net
>> server
>> 127.127.1.0
>> fudge 127.127.1.0
>> driftfile /var/lib/ntp/drift
>>
>>
>>
>>
>>
>>
>>
>> My server log
>> shows:
>>
>>
>> 20 May 14:38:20 xntpd[19386]: synchronized to LOCAL(1), stratum=10
>> 20
>> May 14:39:23 xntpd[19386]: synchronized to 10.2.3.5, stratum=2
>> 20 May 14:54:18
>> xntpd[19386]: time reset (step) -1.014343 s
>> 20 May 14:54:18 xntpd[19386]:
>> synchronisation lost
>> 20 May 14:58:35 xntpd[19386]: synchronized to LOCAL(1),
>> stratum=10
>> 20 May 14:59:38 xntpd[19386]: synchronized to 10.2.3.5, stratum=2
>> 20
>> May 15:14:33 xntpd[19386]: time reset (step) -1.010761 s
>> 20 May 15:14:33 xntpd
>> [19386]: synchronisation lost
>> 20 May 15:16:08 xntpd[13208]: logging to file
>> /var/adm/syslog/ntp.log
>> 20 May 15:16:08 xntpd[13208]: tickadj = 625, tick =
>> 10000, tvu_maxslew =
>> 61875
>> 20 May 15:16:08 xntpd[13208]: precision = 6 usec
>> 20
>> May 15:17:29 xntpd[14031]: logging to file /var/adm/syslog/ntp.log
>> 20 May 15:17:
>> 29 xntpd[14031]: tickadj = 625, tick = 10000, tvu_maxslew =
>> 61875
>> 20 May 15:17:
>> 29 xntpd[14031]: precision = 10 usec
>> 20 May 15:21:46 xntpd[14031]: synchronized
>> to 10.2.3.5, stratum=2
>> 20 May 15:21:46 xntpd[14031]: time reset (step)
>> -0.216182 s
>> 20 May 15:21:46 xntpd[14031]: synchronisation lost
>> 20 May 15:26:03
>> xntpd[14031]: synchronized to LOCAL(1), stratum=10
>> 20 May 15:27:06 xntpd
>> [14031]: synchronized to 10.2.3.5, stratum=2
>> 20 May 15:42:01 xntpd[14031]: time
>> reset (step) -1.005840 s
>> 20 May 15:42:01 xntpd[14031]: synchronisation lost
>> 20
>> May 15:46:18 xntpd[14031]: synchronized to LOCAL(1), stratum=10
>> 20 May 15:47:21
>> xntpd[14031]: synchronized to 10.2.3.5, stratum=2
>> 20 May 16:02:16 xntpd[14031]:
>> time reset (step) -1.009925 s
>> 20 May 16:02:16 xntpd[14031]: synchronisation
>> lost
>> 20 May 16:06:33 xntpd[14031]: synchronized to LOCAL(1), stratum=10
>> 20 May
>> 16:07:36 xntpd[14031]: synchronized to 10.2.3.5, stratum=2
>>
>>
>>
>> nptd -qn shows:
>>
>>
>>
>>
>> remote refid st t when poll reach delay offset
>> disp
>>
>> ==========================================================================
>> ==
>> ==
>>
>> 10.2.3.5 193.204.114.232 2 u 16 64 7 1.92 -158.96 3927.72
>> 127.127.1.1
>> 127.127.1.1 10 l 15 64 17 0.00 0.000
>> 1885.01
>>
>>
>>
>> My time source server is ok
>> (10.2.3.5) and I can exclude problems into my
>> lan.
>>
>>
>>
>> remote local st poll
>> reach delay offset disp
>>
>> =======================================================================
>> =ntp1.
>> nl.uu.net 10.2.3.5 1 1024 377 0.04411 -0.003625 0.12183
>> =ntp1.inrim.it 10.2.3.5
>> 1 1024 377 0.01971 -0.000409 0.12172
>> *ntp2.inrim.it 10.2.3.5 1 1024 377 0.01923
>> -0.000046 0.12175
>> =LOCAL(0) 127.0.0.1 10 64 377 0.00000 0.000000 0.03072
>> =ntp1.
>> rrze.uni-e 10.2.3.5 1 1024 377 0.05191 -0.009084 0.12178
>>
>>
>>
>>
>>
>> Can you indicate
>> suggestions please ? The problem is Offset bigger 128 ms
>> ?!?! Offset is
>> increasing until to 700-800 ms.
>>
>> I run ntpdate to update immediately clock and
>> I can see small offset but
>> after few minutes grows again until to exceed 128
>> ms.
>>
>> How can I solve it ?
>> _______________________________________________
>> questions mailing list
>> questions at lists.ntp.org
>> http://lists.ntp.org/listinfo/questions
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-- 
blu

Always code as if the guy who ends up maintaining your code will be a
violent psychopath who knows where you live. - Martin Golding
-----------------------------------------------------------------------|
Brian Utterback - Solaris RPE, Oracle Corporation.
Ph:603-262-3916, Em:brian.utterback at oracle.com



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