[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>
>>>>>          
>>>>>
>>>>>_______________________________________________
>>>>>questions mailing list
>>>>>questi... at lists.ntp.org
>>>>>https://lists.ntp.org/mailman/listinfo/questions-Hide quoted text -
>>>>>          
>>>>>
>>>>- Show quoted text -
>>>>        
>>>>
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>>>      
>>>
>>- Show quoted text -
>>    
>>
>
>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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>questions mailing list
>questions at lists.ntp.org
>https://lists.ntp.org/mailman/listinfo/questions
>  
>





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