Has anyone got any experience syncing Linux (specifically Red Hat) to a Windows NTP server? Currently our Windows server is syncing to an stratum 1 server on the internet but the Linux boxes refuse to acknowledge it as a good time source.
Having done a bit of research it seems our problem is the Root Dispersion value is possibly too high. Here's the output from ntpq -
ntpq> peers
remote refid st t when poll reach delay offset jitter
==============================================================================
ntp1.ourdomain 10.10.10.1 4 u 20 128 377 0.376 1397.10 22.800
ntpq> ass
ind assID status conf reach auth condition last_event cnt
===========================================================
1 30939 90b4 yes yes none reject reachable 11
ntpq> rv 30939
assID=30939 status=90b4 reach, conf, 11 events, event_reach,
srcadr=ntp1.ourdomain.com, srcport=123, dstadr=10.10.10.2,
dstport=123, leap=00, stratum=4, precision=-6, rootdelay=93.750,
rootdispersion=2333.466, refid=10.10.10.1, reach=377, unreach=0, hmode=3,
pmode=4, hpoll=7, ppoll=7, flash=400 peer_dist, keyid=0, ttl=0,
offset=1369.793, delay=0.000, dispersion=21.915, jitter=15.387,
reftime=d7493cd7.fd3528d6 Mon, Jun 16 2014 10:52:23.989,
org=d74944eb.b857f9bc Mon, Jun 16 2014 11:26:51.720,
rec=d74944ea.5709a581 Mon, Jun 16 2014 11:26:50.339,
xmt=d74944ea.56ea01a7 Mon, Jun 16 2014 11:26:50.339,
filtdelay= 0.48 0.51 0.00 0.43 0.50 0.44 0.40 0.55,
filtoffset= 1380.34 1376.38 1369.79 1362.68 1360.75 1353.16 1349.80 1343.46,
filtdisp= 15.63 17.58 19.48 21.42 23.37 25.30 27.25 29.20
What I'm trying to understand is why this value is so high and is there anything we can configure on the Windows server to change it.
Update
Here's some information from our Windows NTP server -
c:\Windows\System32>w32tm /query /status
Leap Indicator: 0(no warning)
Stratum: 2 (secondary reference - syncd by (S)NTP)
Precision: -6 (15.625ms per tick)
Root Delay: 0.0312500s
Root Dispersion: 1.2097655s
ReferenceId: 0x9E2BC042 (source IP: 158.43.192.66)
Last Successful Sync Time: 18/06/2014 04:41:16
Source: ntp2.pipex.net
Poll Interval: 15 (32768s)
c:\Windows\System32>w32tm /query /peers
#Peers: 2
Peer: ntp1.pipex.net
State: Active
Time Remaining: 6264.1144284s
Mode: 1 (Symmetric Active)
Stratum: 2 (secondary reference - syncd by (S)NTP)
PeerPoll Interval: 15 (32768s)
HostPoll Interval: 15 (32768s)
Peer: ntp2.pipex.net
State: Active
Time Remaining: 6264.1144284s
Mode: 1 (Symmetric Active)
Stratum: 1 (primary reference - syncd by radio clock)
PeerPoll Interval: 15 (32768s)
HostPoll Interval: 15 (32768s)