[ntp:questions] NTP - orphan mode with SAME stratum ("tos orphan 6") FAIL to sync.
David Mills
mills at udel.edu
Mon Apr 6 14:55:59 UTC 2009
sheikdawoodraj... at gmail.com,
I don't understand your question. The interwsection algorithm doesn' t
care if ther are two or twenty parcicipants in the argument.
Dave
sheikdawoodrajali at gmail.com wrote:
>On Apr 3, 12:42 pm, mi... at udel.edu (David Mills) wrote:
>
>
>>sheikdawoodraj... at gmail.com,
>>
>>You might want to review the architecture briefing on the NTP Project
>>Page. Note the definitions of correctness interval, intersection
>>algorithm and majority subset. With only two sources there can be only
>>one majorite subset and that must include both sources. If the
>>correctness intervals do not overlap, neither source is believed and
>>both are marked x. This is not an implmentation matter; it devolves from
>>the theory and has confused many folks in the past.
>>
>>In order to minimuze the grief this can cause if the sources are very
>>precise and have very low synchronization distance, but doffer by more
>>than a few ms, a shim can be added to the correctness interval using the
>>tos mindist comand. The mindist defaults to .005 s by compromise, but
>>you can set it higher to be more forgiving, say .05, should your sources
>>be expected to differ by that much..
>>
>>Dave
>>
>>
>>
>>
>>
>>sheikdawoodraj... at gmail.com wrote:
>>
>>
>>>Thanks for the info.
>>>
>>>
>>>[Dave] Your broadcast clients have very large offsets beyond the
>>>panic threshold (1000 s).
>>>
>>>
>>>>>I verified my configuration file and it has "tinker panic 0" command
>>>>>
>>>>>
>>>present to accept ANY offset value by ntpd service. Let me know if
>>>you
>>>think otherwise
>>>
>>>
>>>[Dave] Easiest way to start is to disable one of the rails and let the
>>>munchkins synchronize, then bring up the second rail.
>>>
>>>
>>>>>I'll do it and let you know.
>>>>>
>>>>>
>>>And also I've seen a "low" offset numbers for both primary/secondary
>>>ONLY
>>>when I start the ntpd service ONE-BY-ONE.
>>>
>>>
>>>For example:
>>>having 7 nodes in the environment, if I stop ALL of them and
>>>start 2 nodes only, the offset values are low and it sync fine.
>>>
>>>
>>>By doing the same way, starting services one-by-one works fine too..
>>>
>>>
>>>It fails only IF ALL of the services started @ once...
>>>
>>>
>>>may be the offset values are higher bcoz of time overlap.
>>>
>>>
>>>QSTN
>>>1) I doubt there could be problem/failures in "Leader" selection
>>>algorithm
>>>implementation in "ORPHAN"mode. Thoughts??
>>>
>>>
>>>2) Running 7 nodes in "ORPHANmodewith same stratum", how to
>>>verify who is the leader?
>>>
>>>
>>>Pls share your thoughts.
>>>
>>>
>>>~ DWD
>>>
>>>
>>>On Apr 3, 8:14 am, mi... at udel.edu (David Mills) wrote:
>>>
>>>
>>>>sheikdawoodraj... at gmail.com,
>>>>
>>>>
>>>>The x's have nothing to do with broadcast or withorphanor with the
>>>>number of hosts, which is unlimited. It has to do with the intersection
>>>>algorithm. Your broadcast clients have very large offsets beyond the
>>>>panic threshold (1000 s). In addition, your prmary and secondary rails
>>>>should be within a few milliseconds of each other or the correctness
>>>>intervals might not overlap. See the docuementation for the tos mindist
>>>>command.
>>>>
>>>>
>>>>Easiest way to start is to disable one of the rails and let the
>>>>munchkins synchronize, then bring up the second rail.
>>>>
>>>>
>>>>Dave
>>>>
>>>>
>>>>sheikdawoodraj... at gmail.com wrote:
>>>>
>>>>
>>>>>I am testing "Time Island" in NTP on Windows platform.
>>>>>I built the binaries using source downloaded from meinberg site.
>>>>>
>>>>>
>>>>>Binaries built successfully and I'm testing it now.
>>>>>
>>>>>
>>>>>NTP on ALL the nodes (7 nodes) with SAME stratum "orphanstratum 6"
>>>>>identically configured
>>>>>both as broadcast client and broadcast server ("Time Island") works
>>>>>fine.
>>>>>
>>>>>
>>>>>Problem:
>>>>>--------------
>>>>>When all the 7 nodes have the same config, using "orphanstratum 6"
>>>>>and using the primary/secondary network broadcast FAILED to time-sync.
>>>>>
>>>>>
>>>>>Time sync was successful ONLY if i do testing <=5 nodes.
>>>>>
>>>>>
>>>>>And the "Selection algorithm tuning parameters" has the belowvalues:
>>>>>#define NTP_MINCLOCK 3 /* min survivors */
>>>>>#define NTP_MAXCLOCK 10 /* max candidates */
>>>>>#define NTP_MAXASSOC 50 /* max associations */
>>>>>
>>>>>
>>>>>Does it mean we cant havemodethan 5 nodes (every node has 2
>>>>>broadcast interfaces, one for primary and other for secondary)
>>>>>configured in the SAME stratum level ?
>>>>>
>>>>>
>>>>>If I have more 7 nodes during the testing, the "ntpq -q" results
>>>>>"X" condition to ALL the nodes during the query.
>>>>>
>>>>>
>>>>>What's the MAX number of nodes that can be used forORPHANmode
>>>>>testing?
>>>>>
>>>>>
>>>>>Any suggestions on this regard are welcome!!
>>>>>
>>>>>
>>>>>BILLBOARD results:
>>>>>------------------------------
>>>>>
>>>>>
>>>>>ntpq>
>>>>>peers
>>>>> remote refid st t when poll reach delay
>>>>>offset jitter
>>>>>==========================================================================
>>>>>
>>>>>
>>====
>>
>>
>>>>>39.95.255.255 .BCST. 16 u - 64 0 0.000
>>>>>0.000 0.001
>>>>>39.111.255.255 .BCST. 16 u - 64 0 0.000
>>>>>0.000 0.001
>>>>>x39.92.128.6 127.0.0.1 6 u 59 64 376 0.236
>>>>>-130361 1.410
>>>>>x39.108.128.6 127.0.0.1 6 u 53 64 376 0.174
>>>>>-130361 1.396
>>>>>x39.98.208.6 127.0.0.1 6 u 61 64 376 0.210
>>>>>-548318 2.975
>>>>>x39.82.208.6 127.0.0.1 6 u 60 64 376 0.218
>>>>>-548318 2.541
>>>>>x39.81.224.16 127.0.0.1 6 u 42 64 376 0.393
>>>>>-455581 1.901
>>>>>x39.97.224.16 127.0.0.1 6 u 48 64 377 0.390
>>>>>-455581 1.621
>>>>>x39.81.224.15 127.0.0.1 6 u 45 64 376 0.216
>>>>>-455603 0.695
>>>>>x39.97.224.15 127.0.0.1 6 u 36 64 376 0.502
>>>>>-455604 0.698
>>>>>x39.81.224.6 127.0.0.1 6 u 43 64 377 0.176
>>>>>1059871 0.968
>>>>>x39.97.224.6 127.0.0.1 6 u 45 64 376 0.245
>>>>>1059868 0.815
>>>>>x39.97.64.6 127.0.0.1 6 u 29 64 376 0.236
>>>>>42.836 3.811
>>>>>x39.81.64.6 127.0.0.1 6 u 24 64 377 0.194
>>>>>43.809 4.880
>>>>>ntpq>
>>>>>
>>>>>
>>>>>ntpq>
>>>>>assoc
>>>>>
>>>>>
>>>>>ind assID status conf reach auth condition last_event
>>>>>cnt
>>>>>===========================================================
>>>>>1 37893 c000 yes yes bad
>>>>>reject
>>>>>2 37894 c000 yes yes bad
>>>>>reject
>>>>>3 37895 7114 no yes ok falsetick reachable
>>>>>1
>>>>>4 37896 7114 no yes ok falsetick reachable
>>>>>1
>>>>>5 37897 7114 no yes ok falsetick reachable
>>>>>1
>>>>>6 37898 7114 no yes ok falsetick reachable
>>>>>1
>>>>>7 37899 7114 no yes ok falsetick reachable
>>>>>1
>>>>>8 37900 7114 no yes ok falsetick reachable
>>>>>1
>>>>>9 37901 7114 no yes ok falsetick reachable
>>>>>1
>>>>>10 37902 7114 no yes ok falsetick reachable
>>>>>1
>>>>>11 37903 7114 no yes ok falsetick reachable
>>>>>1
>>>>>12 37904 7114 no yes ok falsetick reachable
>>>>>1
>>>>>13 37905 7114 no yes ok falsetick reachable
>>>>>1
>>>>>14 37906 7114 no yes ok falsetick reachable
>>>>>1
>>>>>ntpq>
>>>>>
>>>>>
>>>>>ntpq>
>>>>>passoc
>>>>>
>>>>>
>>>>>ind assID status conf reach auth condition last_event
>>>>>cnt
>>>>>===========================================================
>>>>>1 37893 c000 yes yes bad
>>>>>reject
>>>>>2 37894 c000 yes yes bad
>>>>>reject
>>>>>3 37895 7114 no yes ok falsetick reachable
>>>>>1
>>>>>4 37896 7114 no yes ok falsetick reachable
>>>>>1
>>>>>5 37897 7114 no yes ok falsetick reachable
>>>>>1
>>>>>6 37898 7114 no yes ok falsetick reachable
>>>>>1
>>>>>7 37899 7114 no yes ok falsetick reachable
>>>>>1
>>>>>8 37900 7114 no yes ok falsetick reachable
>>>>>1
>>>>>9 37901 7114 no yes ok falsetick reachable
>>>>>1
>>>>>10 37902 7114 no yes ok falsetick reachable
>>>>>1
>>>>>11 37903 7114 no yes ok falsetick reachable
>>>>>1
>>>>>12 37904 7114 no yes ok falsetick reachable
>>>>>1
>>>>>13 37905 7114 no yes ok falsetick reachable
>>>>>1
>>>>>14 37906 7114 no yes ok falsetick reachable
>>>>>1
>>>>>ntpq>
>>>>>
>>>>>
>>>>>ntpq>
>>>>>readvar
>>>>>assID=0 status=0011 leap_none, sync_unspec, 1 event,
>>>>>event_restart,
>>>>>version="ntpd 4.2.... at 1.1541-o Mar 15 23:23:09.92 (UTC-07:00) 2009
>>>>>(12)",
>>>>>processor="unknown", system="WINDOWS/NT", leap=00,
>>>>>stratum=6,
>>>>>precision=-20, rootdelay=0.000, rootdispersion=0.030,
>>>>>peer=0,
>>>>>refid=127.0.0.1, reftime=00000000.00000000 --- --- -- ----
>>>>>--:--:--,
>>>>>poll=6, clock=cd7b6f4c.4b49fb4e Mon, Mar 30 2009 17:18:20.294,
>>>>>state=0,
>>>>>offset=0.000, frequency=0.000, jitter=0.001,
>>>>>noise=0.001,
>>>>>stability=0.000,
>>>>>tai=0
>>>>>ntpq>
>>>>>
>>>>>
>>>>>ntpdc>
>>>>>listpeers
>>>>>broadcast
>>>>>39.95.255.255
>>>>>control
>>>>>39.81.64.6
>>>>>broadcast
>>>>>39.111.255.255
>>>>>control
>>>>>39.97.64.6
>>>>>control
>>>>>39.92.128.6
>>>>>control
>>>>>39.81.224.6
>>>>>control
>>>>>39.108.128.6
>>>>>control
>>>>>39.81.224.15
>>>>>control
>>>>>39.82.208.6
>>>>>control
>>>>>39.81.224.16
>>>>>control
>>>>>39.97.224.6
>>>>>control
>>>>>39.97.224.15
>>>>>control
>>>>>39.98.208.6
>>>>>control
>>>>>39.97.224.16
>>>>>ntpdc>
>>>>>
>>>>>
>>>>>ntpdc>
>>>>>sysstats
>>>>>time since restart:
>>>>>2958
>>>>>time since reset:
>>>>>2958
>>>>>packets received:
>>>>>869
>>>>>packets processed:
>>>>>630
>>>>>current version:
>>>>>741
>>>>>previous version:
>>>>>0
>>>>>bad version:
>>>>>0
>>>>>access denied:
>>>>>92
>>>>>bad length or format:
>>>>>0
>>>>>bad authentication:
>>>>>0
>>>>>rate exceeded:
>>>>>0
>>>>>ntpdc>
>>>>>
>>>>>
>>>>>ntpdc>
>>>>>sysinfo
>>>>>system peer:
>>>>>0.0.0.0
>>>>>system peermode:
>>>>>unspec
>>>>>leap indicator:
>>>>>00
>>>>>stratum:
>>>>>6
>>>>>precision:
>>>>>-20
>>>>>root distance: 0.00000
>>>>>s
>>>>>root dispersion: 0.00002
>>>>>s
>>>>>reference ID:
>>>>>[127.0.0.1]
>>>>>reference time: 00000000.00000000 --- --- -- ----
>>>>>--:--:--
>>>>>system flags: bclient auth monitor ntp kernel
>>>>>stats
>>>>>jitter: 0.000000
>>>>>s
>>>>>stability: 0.000
>>>>>ppm
>>>>>broadcastdelay: 0.003998
>>>>>s
>>>>>authdelay: 0.000006
>>>>>s
>>>>>ntpdc>
>>>>>
>>>>>
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>>>>>
>>>>>
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>>>>
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>>
>>
>
>Mills,
>Thank you very much for your explanation.
>
>I went through the definitions of NTP "correctness interval,
>intersection
>algorithm and majority subset".
>
>The broadcast was successful after adding shim (Setting "tos mindist
>0.010")
>to the correctness interval. It worked fine once but when I tried
>again the time-sync
>was -not- successful. Could it be a problem in the network
>configuration(s) -or-
>something else ?
>
>[Mills] The intersection algorithm is discarding all packets because
>you
>have only two sources and there is no majority subset.
>
>[Dawood] I assume the systems with SAME stratum "orphan stratum 6"
>identically
>configured both as broadcast client and broadcast server ("Time
>Island") will
>work fine WITHOUT a shim IF there are more than TWO sources??
>
>Thanks,
>Dawood
>
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