03-19-2010 08:20 AM - edited 03-06-2019 10:13 AM
Hi All,
Please help me to understand the situation and solve it
My devices start to run on BST two weeks earlier that it actually DST starts on Sunday, 28 March 2010, 01:00 local standard time DST endson Sunday, 31 October 2010, 02:00 local daylight time. The device is synchronized with 127.127.7.1 what is this IP and why it has considered it as Sync master
Swtich6500#sh run | in cloc
clock timezone gmt 0
clock summer-time bst recurring
Swtich6500#sh run | in ntp
ntp master
ntp server 10.49.112.33
ntp server 10.49.112.34
Swtich6500#sh clock
15:53:25.263 bst Fri Mar 19 2010
Swtich6500#sh ntp ass
address ref clock st when poll r each delay offset disp
*~127.127.7.1 127.127.7.1 7 16 64 377 0.0 0.00 0.0
~10.49.112.33 0.0.0.0 16 - 1024 0 0.0 0.00 16000.
~10.49.112.34 0.0.0.0 16 - 1024 0 0.0 0.00 16000.
* master (synced), # master (unsynced), + selected, - candidate, ~ configured
Swtich6500#sh ntp status
Clock is synchronized, stratum 8, reference is 127.127.7.1
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**24
reference time is CF4E0E60.EA4EBF4A (15:53:20.915 bst Fri Mar 19 2010)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.02 msec, peer dispersion is 0.02 msec
Swtich6500#sh clock de
15:54:02.975 bst Fri Mar 19 2010
Time source is NTP
Summer time starts 02:00:00 gmt Sun Mar 14 2010
Summer time ends 02:00:00 bst Sun Nov 7 2010
The device config which is acting as NTP master to the above mentioned device:-
CoreSwtich#sh run | in clock
clock timezone gmt 0
clock summer-time bst recurring
ntp clock-period 17179923
CoreSwtich#sh clock de
16:07:53.856 bst Fri Mar 19 2010
Time source is NTP
Summer time starts 02:00:00 gmt Sun Mar 14 2010
Summer time ends 02:00:00 bst Sun Nov 7 2010
CoreSwtich#sh run | in ntp
ntp clock-period 17179923
ntp source Loopback0
ntp master
ntp server X.X.X.101
ntp server X.X.X.100
ntp server X.X.X.102
CoreSwtich#sh ntp ass
address ref clock st when poll reach delay offset disp
+ 10.200.0.36 10.49.110.12 4 868 1024 377 -9.2 -73.35 31.7
~127.127.7.1 127.127.7.1 7 1 64 377 0.0 0.00 0.0
- 10.54.99.11 10.49.110.12 4 935 1024 377 -13.4 -101.6 51.8
* ~X.X.X.101 X.X.X.132 3 711 1024 377 4.5 -86.51 37.4
+ ~X.X.X.100 X.X.X.252 3 260 1024 377 1.8 11.23 136.3
+ ~X.X.X.102 X.X.X.106 3 720 1024 377 1.9 -24.32 28.2
* master (synced), # master (unsynced), + selected, - candidate, ~ configured
CoreSwtich#
Thanks
Jagdev
Solved! Go to Solution.
03-20-2010 08:19 AM
Hi
Thanks for your help, I got idea why it has change on 14 March because in American Region it changing on DST started on Sunday, 14 March 2010, 02:00 local standard time DST ends on Sunday, 7 November 2010, 02:00 local daylight time Most of North America Springs Forward March 14, 2010 .
where as my device are situated in London, UK.
I need some more help why it has synced with 127.127.7.1 where as the device which is serving as master is working fine and it just next hope.
Regards
Jagdev
Hi Jagdev,
For your question why it gets synced with 127.127.7.1 is because “127.127.7.1” is the internal server created by ntp master command, which the local router synchronizes to and in your first post if you see in your switch you have configured as ntp master under ntp configuration.
Hope to Help !!
Remember to rate the helpful post
Ganesh.H
03-19-2010 08:35 AM
Hi,
the command reference guide (http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_03.html#wp1013813 ) says"
"If the clock summer-time zone recurring command is specified without parameters, the summer time rules default to United States rules."
Which is your case, I'm afraid, "bst" is just a "Name of the time zone (for example, "PDT" for Pacific Daylight Time) to be displayed when summer time is in effect. The length of the zone argument is limited to 7 characters.", as the guide says.
HTH,
Milan
03-19-2010 11:38 PM
Hi
Thanks for your help, I got idea why it has change on 14 March because in American Region it changing on DST started on Sunday, 14 March 2010, 02:00 local standard time DST ends on Sunday, 7 November 2010, 02:00 local daylight time Most of North America Springs Forward March 14, 2010 .
where as my device are situated in London, UK.
I need some more help why it has synced with 127.127.7.1 where as the device which is serving as master is working fine and it just next hope.
Regards
Jagdev
03-20-2010 08:19 AM
Hi
Thanks for your help, I got idea why it has change on 14 March because in American Region it changing on DST started on Sunday, 14 March 2010, 02:00 local standard time DST ends on Sunday, 7 November 2010, 02:00 local daylight time Most of North America Springs Forward March 14, 2010 .
where as my device are situated in London, UK.
I need some more help why it has synced with 127.127.7.1 where as the device which is serving as master is working fine and it just next hope.
Regards
Jagdev
Hi Jagdev,
For your question why it gets synced with 127.127.7.1 is because “127.127.7.1” is the internal server created by ntp master command, which the local router synchronizes to and in your first post if you see in your switch you have configured as ntp master under ntp configuration.
Hope to Help !!
Remember to rate the helpful post
Ganesh.H
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