[ntp:questions] Is a high-stratum falseticker possible? Complex configuration and unexpected result
rumegauu at ugpa.ru
rumegauu at ugpa.ru
Thu Apr 26 10:39:59 UTC 2012
Hello,
I designed a complex configuration for a huge intranet network some
time ago. The network is completely isolated from the Internet and
uses internal time sources. Circuits aren't any good there, so I
decided to use some peer-to-peer synchronization in addition to the
main hierarchy and enabled tos orphan.
I hardly need to say that most of the hosts are embedded devices which
aren’t easily accessible. I've built ntp4.2.6 from the tarball and
deployed it across the devices. Various simulations were passed with
success before the launch in 2011. It has been running well for 6
months until some unexpected troubles come.
Could you explain to me HOW this is possible? The prime server with
stratum 6 declared falseticker, when the peer with stratum 12 is
considered to be true.
NTPQ output:
C:\Users\public> ntpq -n 25.18.0.124
ntpq> raw
Output set to raw
ntpq> pe
remote refid st t when poll reach delay
offset jitter
==============================================================================
x25.18.0.235 LOCAL(0) 6 u 272 128 377 17.354
90575.7 4.384
x25.18.0.103 25.18.0.235 7 u 302 128 377 37.938
34576.2 95.391
x25.18.0.105 25.18.0.116 12 u 805 1024 376 52.333
3418.78 29.265
25.18.0.106 25.18.0.124 12 u 277 1024 377 39.883
14.698 24.281
x25.18.0.107 25.18.0.113 11 u 713 1024 376 184.678 1175.09
778.300
*25.18.0.108 25.18.0.112 12 u 457 1024 367 77.007
-6.868 81.954
-25.18.0.109 25.18.0.115 13 u 222 1024 377 103.053
-318.49 54.671
25.18.0.112 25.18.0.109 11 u 615 1024 355 83.708
-101.42 49.904
25.18.0.113 127.0.0.1 10 u 1220 1024 376 112.932
-145.68 32.612
x25.18.0.114 25.18.0.118 13 u 1050 1024 376 6.649 -35174.
487.947
+25.18.0.115 25.18.0.112 13 u 589 1024 356 68.001
5.703 30.844
25.18.0.116 25.18.0.124 13 u 210 1024 377 50.452
-42.981 29.490
-25.18.0.118 25.18.0.116 12 u 387 1024 377 38.929
-103.65 42.252
+25.18.0.122 25.18.0.115 13 u 697 1024 376 26.176
-10.287 33.839
x25.18.0.123 25.18.0.115 13 u 886 1024 376 10.380
5543.16 75.828
25.18.0.124 .INIT. 16 u - 1024 0 0.000
0.000 0.000
ntpq> rv
associd=0 status=0x0618,
version="ntpd 4.2.6p1 at 1.2158 Tue Sep 21 11:13:30 UTC 2010 (1)",
processor="x86pc", system="QNX/6.3.2", leap=0, stratum=11,
precision=-10, rootdelay=103.053, rootdisp=421.974, refid=25.18.0.109,
reftime=0xd339131d.ef9d3607, clock=0xd339175b.844810af, peer=52456,
tc=10, mintc=3, offset=-318.499, frequency=-13.848, sys_jitter=82.308,
clk_jitter=99.267, clk_wander=0.029
ntpq> as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 52450 9124 yes yes none falsetick reachable 2
2 52451 9124 yes yes none falsetick reachable 2
3 52452 9124 yes yes none falsetick reachable 2
4 52453 901a yes yes none reject sys_peer 1
5 52454 9124 yes yes none falsetick reachable 2
6 52455 961a yes yes none sys.peer sys_peer 1
7 52456 933a yes yes none outlyer sys_peer 3
8 52457 901a yes yes none reject sys_peer 1
9 52458 901a yes yes none reject sys_peer 1
10 52459 9124 yes yes none falsetick reachable 2
11 52460 941a yes yes none candidate sys_peer 1
12 52461 901a yes yes none reject sys_peer 1
13 52462 931a yes yes none outlyer sys_peer 1
14 52463 941a yes yes none candidate sys_peer 1
15 52464 9124 yes yes none falsetick reachable 2
16 52465 8011 yes no none reject mobilize 1
ntpq> rv 52456
associd=52456 status=0x933a,
srcadr=25.18.0.109, srcport=123, dstadr=25.18.0.124, dstport=123,
leap=0, stratum=13, precision=-10, rootdelay=126.938,
rootdisp=682.297,
refid=25.18.0.115, reftime=0xd339128e.863bdce7,
rec=0xd339173c.e54e2599,
reach=0xff, unreach=0, hmode=1, pmode=1, hpoll=10, ppoll=10,
headway=583, flash=0x0, keyid=0, offset=-318.499, delay=103.053,
dispersion=28.132, jitter=54.671, xleave=1.476,
filtdelay= 114.41 103.05 260.30 219.31 151.17 117.18 129.10 203.67,
filtoffset= -288.54 -318.50 -397.15 -386.71 -356.67 -339.87 -359.52
-393.27,
filtdisp= 1.95 17.78 33.64 49.52 65.18 81.41 96.89 112.42
The config file on 25.18.0.124 is similar that:
server 25.18.0.235 iburst minpoll 4 maxpoll 7
server 25.18.0.103 iburst minpoll 4 maxpoll 7
peer 25.18.0.105 minpoll 10
peer 25.18.0.106 minpoll 10
peer 25.18.0.107 minpoll 10
peer 25.18.0.108 minpoll 10
peer 25.18.0.109 minpoll 10
peer 25.18.0.112 minpoll 10
peer 25.18.0.113 minpoll 10
peer 25.18.0.114 minpoll 10
peer 25.18.0.115 minpoll 10
peer 25.18.0.116 minpoll 10
peer 25.18.0.118 minpoll 10
peer 25.18.0.122 minpoll 10
peer 25.18.0.123 minpoll 10
peer 25.18.0.124 minpoll 10
tos orphan 12
tos maxdist 5
tinker panic 0
disable auth
driftfile /var/ntp.drift
Thank you for any help you can provide.
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