NTP server advice - Page 2

Walsby1983 · ‎02-27-2012

Hello, i'm having issues getting various model switches to sync with a newly built NTP (Win2008) server with Atomic clock attached to it. The software for the clock is set to stratum 1. I know the clock is syncronising and the server is showing the correct time also. THe server currently has the firewall turned off so no traffic is being blocked to it.

I have the below on all switches;

clock timezone GMT 0

Clock summer-time GMT recurring last Sun Mar 1:00 last Sun Oct 2:00

and

ntp server 10.0.101.15 (ip of the above server)

Currently is have a core switch (4507R) that will not sync at all;

sh clock

*23:59:53.989 GMT Wed Mar 16 2011

sh ntp as

address ref clock st when poll reach delay offset dis

~10.0.101.15 .LOCL. 1 141 1024 377 0.0 300258 8.

* master (synced), # master (unsynced), + selected, - candidate, ~ configured

sh ntp status

Clock is unsynchronized, stratum 16, no reference clock

nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18

reference time is 00000000.00000000 (00:00:00.000 GMT Mon Jan 1 1900)

clock offset is 0.0000 msec, root delay is 0.00 msec

root dispersion is 0.00 msec, peer dispersion is 0.00 msec

I also have multiple access switches (3550's, 3750's,3548's) that must have synced at some point as they were originally showing a 1993 date but are now up to date but not sync'd properly;

sh clock

.12:28:06.346 GMT Mon Feb 27 2012

sh ntp as

address ref clock st when poll reach delay offset disp

~10.0.101.15 .LOCL. 1 326 1024 377 9.7 121575 352.5

* master (synced), # master (unsynced), + selected, - candidate, ~ configured

sh ntp status

Clock is unsynchronized, stratum 16, no reference clock

nominal freq is 381.4697 Hz, actual freq is 381.4697 Hz, precision is 2**17

reference time is D2ECEEC7.7AB25EFE (16:09:43.479 GMT Mon Feb 20 2012)

clock offset is -782401.5959 msec, root delay is 1.37 msec

root dispersion is 782590.12 msec, peer dispersion is 188.52 msec

Is there a way to force synchronisation or is a reboot of the device needed for them to sync?

Thanks in advance, any advice appreicated.

Walsby1983 · ‎02-28-2012

Thanks Kunal, if i add that to the config I get

sh ntp status;

Clock is synchronized, stratum 3, reference is 127.127.7.1

nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**7

reference time is D2F72BBF.EE855780 (10:32:31.931 GMT Tue Feb 28 2012)

clock offset is 0.0000 msec, root delay is 0.00 msec

root dispersion is 7.81 msec, peer dispersion is 7.81 msec

sh ntp as;

address ref clock st when poll reach delay offset disp

*~127.127.7.1 127.127.7.1 2 13 64 377 0.0 0.00 7.8

~10.0.101.15 .LOCL. 1 92 1024 377 0.0 691245 944.1

* master (synced), # master (unsynced), + selected, - candidate, ~ configured

Isnt this setting it as a master for other devices even though not synced with the actual NTP server?

tyagikunal · ‎02-28-2012

please configure below command in master cisco switch and please share ntp configuration for core switch (4507R)

ntp update-calendar

Walsby1983 · ‎02-28-2012

!

ntp update-calendar

ntp server 10.0.101.15

!

end

Below is the debug info from the Timesync software;

Timesync NTP Service 3.2

Windows Info

Version=6.1 Build 7601 0601

Winsock Info

Version=1.1

HighVersion=2.2

Description=WinSock 2.0

Status=Running

MaxSockets=32767

MaxUDP=65467

Timezone Info

Bias=0

Standard Name=GMT Standard Time

Standard Bias=0

Standard date=0/10/5 2:0:0:0

Daylight Name=GMT Daylight Time

Daylight Bias=-60

Daylight date=0/3/5 1:0:0:0

The server has UTC 0 timezone - would this affect it as I have GMT in the switch configs...

Richard Burts · ‎02-29-2012

Alan

You are quite correct that if you configure any Cisco device with the ntp master command then you have instructed that device that it should consider itself authoritative for NTP and it will offer NTP time to anything that asks. But it still has only its own (somewhat undependable) clock as the source for time. I urge you to not do this and to find what is preventing the Cisco from sync with the server that has the atomic clock.

Is this the timesync from ravib? I have looked at what they say on their website and it looks like it is requesting time from the atomic clock at Boulder. That would be good for setting the time in the PC. But it does not look like it runs an implementation of NTP that would support the PC acting as an authoritative NTP server. If the server is learning good NTP time but is running the regular Windows time service for sharing time with other devices then this would explain why your Cisco switches are not getting sync with the server.

HTH

Rick

HTH

Rick