[ntp:questions] NTP not syncing to configured servers

Chandra Kanth kckanth21 at gmail.com
Thu May 14 04:29:22 UTC 2015


FYI,

This is the way we add server, so we are using iburst option already.

addserver 10.126.142.198 0  3  iburst minpoll 4 maxpoll 4

Thanks
Chandrakanth

On Wed, May 13, 2015 at 10:31 PM, Dallas Graves <dallasg79 at gmail.com> wrote:

> Can you clarify if you’re setting “stratum 5” on your target servers, or
> your local “fudge” server?
>
> As far as I know, remote NTP servers should not require stratum option.  I
> only use this option on my local time source, and by that I mean issuing a
> rather high value as to ensure that it’s selected last.  One thing you may
> want to try is using iburst option which instructs NTP to issue 8 request
> packets if the first is not received, this often helps with network-related
> issues (which you may or may not be experiencing).
>
> If this is not helpful, perhaps you could sanitize your config and share
> it with the mailing list so we can better help you?
>
> Thanks,
> -Dallas
>
>
> On May 13, 2015, at 11:08 AM, Chandra Kanth <kckanth21 at gmail.com> wrote:
>
> OK. Lets rule out its ACL/firewall issue. I have been able to use ntpdate
> -d command. I used it several times on this setup.
>
> Next, do you think arbitrary setting of stratum to low value such as 5 is
> problem?
> FYI, these servers are high end routers, so that's why we set its stratum
> to 5.
>
> On what basis we should set stratum value? What is the appropriate value?
> How do we determine what should be the stratum?
>
> Regards
> Chandrakanth
>
> On Wed, May 13, 2015 at 9:33 PM, Dallas Graves <dallasg79 at gmail.com>
> wrote:
>
>> Your question is quite clear.  As I stated, you want to ensure that you
>> can, in fact, access the targeted NTP servers via the debug switch in the
>> ntpdate command.  If you’ve confirmed that access is not blocked by
>> firewall and/or ACL, then you’ll want to make sure you set the stratum
>> correctly in the ntp.conf configuration, ensuring that your fudge or (local
>> time source) is set at a higher stratum such as 10.
>>
>> Hope this helps.
>>
>> -Dallas
>>
>>
>>
>> On May 13, 2015, at 10:58 AM, Chandra Kanth <kckanth21 at gmail.com> wrote:
>>
>> Hi Graves, Yu,
>>
>> First of all thanks for response. Let me clarify, this is private lab
>> setup, no public ntp servers.
>> The idea is to setup private ntp subnet, where the time on servers such
>> as .198 and .204 should be propagated to other clients.
>>
>> Think as .198 and .204 as private ntp servers which is configured as
>> lower stratum server. (i.e. /etc/ntp.conf contains stratum 5). So these
>> servers does not get a reference clock from any other lower stratum i.e.
>> stratum 4. It simply provides system time from its own local clock.
>>
>> The client here which .196 is running at higher stratum i.e. 10.
>>
>> So I'm was hoping the client (.196) should sync to any one of the server
>> since at least their stratum is lower.
>>
>> I hope the question is clear.
>>
>> Regards
>> Chandrakanth
>>
>>
>> On Wed, May 13, 2015 at 7:42 PM, Dallas Graves <dallasg79 at gmail.com>
>> wrote:
>>
>>> To expound upon Yu’s comment.  If you don’t have access to the firewall,
>>> a good check would be to conduct a test against each of your targeted NTP
>>> servers with the “ntpdate -d” command, which is the debug switch and will
>>> let you know if you can or cannot reach the intended systems.
>>>
>>> -Dallas
>>>
>>>
>>> > On May 13, 2015, at 8:54 AM, Wang, Yu <ywang10 at fsu.edu> wrote:
>>> >
>>> > Do your ntp servers have public IP addresses configured or do you do
>>> NAT for the two ntp servers? 10.126.142.198 and 10.126.142.204 are private
>>> addresses and won't be routed over the Internet.
>>> > The second place to check is firewall. Make sure it opens to upd/123
>>> between your ntp servers and outside ntp servers.
>>> >
>>> > Yu
>>> > Core Networking, FSU
>>> >
>>> >
>>> > -----Original Message-----
>>> > From: questions [mailto:questions-bounces+ywang10=
>>> fsu.edu at lists.ntp.org] On Behalf Of Chandrakanth K
>>> > Sent: Wednesday, May 13, 2015 7:52 AM
>>> > To: questions at lists.ntp.org
>>> > Subject: [ntp:questions] NTP not syncing to configured servers
>>> >
>>> > Hi,
>>> >
>>> > I am seeing ntp not syncing to external configured servers. We tried
>>> both 4.2.4 and 4.2.6 versions.
>>> > The following is the configuration,
>>> >
>>> > We use two servers 10.126.142.198 and 10.126.142.204 in our Lab.
>>> > They are statically configured as running @ stratum level 5 and
>>> providing the clock from its own local clock.
>>> >
>>> > Even though the servers does not have a valid reference time and
>>> provides time from its own clock, according to me still we need to be able
>>> to sync to it since it is running at better stratum.
>>> > Please clarify.
>>> >
>>> > Logs:
>>> > -------------------------
>>> >
>>> > bash-4.2$ ntpq -np -c assoc
>>> >     remote           refid      st t when poll reach   delay   offset
>>> jitter
>>> >
>>> ==============================================================================
>>> > *127.127.1.0     .LOCL.          10 l   19   64  377    0.000
>>> 0.000   0.001
>>> > 10.126.142.198      LOCAL(0)         6 u    7   16  377    0.172
>>> 859.844   0.501
>>> > 10.126.142.204      LOCAL(0)         6 u   15   16  377    0.227
>>> 1057.22   0.240
>>> >
>>> > ind assID status  conf reach auth condition  last_event cnt
>>> ===========================================================
>>> >  1 26554  9614   yes   yes  none  sys.peer   reachable  1
>>> >  2 26555  9014   yes   yes  none    reject   reachable  1
>>> >  3 26556  9014   yes   yes  none    reject   reachable  1
>>> >
>>> > Logs: 10.126.142.198
>>> > -----------------------------------
>>> > bash-4.2$ ntpq -np -c assoc
>>> >     remote           refid      st t when poll reach   delay   offset
>>> jitter
>>> >
>>> ==============================================================================
>>> > *127.127.1.0     .LOCL.           5 l   10   64  377    0.000
>>> 0.000   0.000
>>> >
>>> > ind assid status  conf reach auth condition  last_event cnt
>>> ===========================================================
>>> >  1 48508  965a   yes   yes  none  sys.peer    sys_peer  5
>>> >
>>> >
>>> > Logs: 10.126.142.204
>>> > -----------------------------------
>>> >
>>> > bash-4.2$ ntpq -np -c assoc
>>> >     remote           refid      st t when poll reach   delay   offset
>>> jitter
>>> >
>>> ==============================================================================
>>> > *127.127.1.0     .LOCL.           5 l   13   64  377    0.000
>>> 0.000   0.000
>>> >
>>> > ind assid status  conf reach auth condition  last_event cnt
>>> ===========================================================
>>> >  1 32737  963a   yes   yes  none  sys.peer    sys_peer  3
>>> >
>>> >
>>> > Regards
>>> > Chandrakanth
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>>
>>
>>
>
>


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