Cisco Cisco TelePresence Video Communication Server Expressway 문제 해결 가이드
NTP server
Cisco VCS troubleshooting procedures
Page 8 of 9
NTP server
To gather more information for problems with NTP on the VCS, log in as root and type:
ntpq
At the “ntpq>” prompt type “as”:
ntpq> as
Results such as the following should be seen:
ind assid status conf reach auth condition last_event cnt
===========================================================
1 7696 961d yes yes none sys.peer 1
If this returns a blank please check that DNS is configured.
Make a note of the number in the “assid” column for each entry and then type:
rv <assid number>
All the variables ntpq has associated with that NTP server will be printed and will look similar to the
following:
following:
ntpq> rv 7696
associd=7696 status=961d conf, reach, sel_sys.peer, 1 event, popcorn,
srcadr=adc-sjc2-c1-4-w.cisco.com, srcport=123, dstadr=10.50.152.92,
dstport=123, leap=00, stratum=4, precision=-6, rootdelay=269.989,
rootdisp=115.555, refid=72.163.56.103,
reftime=d21c2d01.11365bdc Thu, Sep 15 2011 7:51:29.067,
rec=d21c2d4c.d5627e75 Thu, Sep 15 2011 7:52:44.833, reach=377,
unreach=0, hmode=3, pmode=4, hpoll=10, ppoll=10, headway=0, flash=00 ok,
keyid=0, offset=27.581, delay=179.317, dispersion=15.669, jitter=7.882,
xleave=0.034,
filtdelay= 180.61 220.79 179.32 183.55 179.42 179.40 180.28 180.22,
filtoffset= 27.01 6.87 27.58 25.42 27.45 27.40 26.97 26.94,
filtdisp= 15.63 15.66 15.69 15.72 15.75 15.78 15.81 15.84
It is important to note the flash code if the VCS is failing to synchronize with the NTP server. The flash
code details the reason for the NTP not synchronizing. A list of the flash codes and their meaning can
be retrieved from
code details the reason for the NTP not synchronizing. A list of the flash codes and their meaning can
be retrieved from
In some instances, Windows NTP servers that use their own internal clock as a reference time can
give a “peer_dist” flash code. This may be due to the localclockdispersion registry value (located at
“HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Config”) being set too high. NTPQ will not
synchronize with a server if it believes the error value the NTP server has on its time is too high. Time
servers referencing their own internal clocks should only be used if no other NTP server is available.
In this case it is safe to reduce the dispersion to 0. In all other cases a properly referenced time server
should be used.
give a “peer_dist” flash code. This may be due to the localclockdispersion registry value (located at
“HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Config”) being set too high. NTPQ will not
synchronize with a server if it believes the error value the NTP server has on its time is too high. Time
servers referencing their own internal clocks should only be used if no other NTP server is available.
In this case it is safe to reduce the dispersion to 0. In all other cases a properly referenced time server
should be used.