09-02-2010 10:33 AM - edited 03-06-2019 12:47 PM
Hallo,
I have a great problem with our time synchronization. In our network there are two switches Cisco 3750E (as coreswitch). One of them (first) has a default ntp (server external) but the other switch cannot sync the time from the first switch. The time from the second switch is after 15 minutes.
How can I sync this second switch with the first one? Which command can I use to sync a switch with another source?
#conf t
config#ntp server 192.168... ..
It does not work. The server is registered but not sync...
fyi:
#show ntp associations
adress ref clock st when poll reach
+~192.53.103.108 .PTB. 1 477 1024 377
* ~192.53.103.104 .PTB. 1 160 1024 377
Thanks for your help!
Best regards,
Alex
09-02-2010 11:56 AM
Hi Alex,
You can configure the first switch as a master ntp server using "ntp master"
The second switch should be able to sync with the first switch after that.
http://www.cisco.com/en/US/docs/ios/12_1/configfun/configuration/guide/fcd303.html#wp1001170
Tim
09-02-2010 06:40 PM
Alex
I am not understanding your question. It asks about problems in achieving sync but the command output that you shows clearly says that the device has successfully established sync. Where is the problem?
HTH
Rick
09-03-2010 05:31 AM
Hello Rick,
its correct that the sync is successfully. But we have a false time. If I use the "#show ntp status" command I get following information:
Clock is synchronized, stratum 2, reference is 192.53.103.104
nominal freq is 119.2092 Hz, actual freq is 119.2160 Hz, precision is 2**18
reference time is D02B6219.F44C77D3 (14:01:29.954 mest Fri Sep 3 2010)
clock offset is -30.7319 msec, root delay is 80.57 msec
root dispersion is 158.34 msec, peer dispersion is 132.11 msec
But our real time clock is 14:15. (15min after)
What can I do? We need the correct time urgently.
Best regards,
Alex
09-03-2010 05:56 AM
Alex
I have never known one of the sources of NTP on the Internet to be off by 15 minutes and am very puzzled what could be causing your symptoms. Perhaps if you were to post the configuration of the switch we might find something.
The only other suggestion that I have at this point might be to try using a different NTP source in the Internet and see if you get different results.
HTH
Rick
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