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Cisco Router (IOS) not syncing with NTP Server (unsynchronized)


We are trying to get one of our routers to synchronise with a NTP server. We have a pretty simple config but we can't get it to synchronise.

This is our config:

ntp access-group serve-only 15
ntp server 94.125.132.7

This is the result of show ntp associations:

  address         ref clock     st  when  poll reach  delay  offset    disp
 ~94.125.132.7     0.0.0.0          16     -    64    0     0.0    0.00  16000.
 * master (synced), # master (unsynced), + selected, - candidate, ~ configured

This is the result of show ntp status

Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 249.5901 Hz, actual freq is 249.5907 Hz, precision is 2**16
reference time is 00000000.00000000 (00:00:00.000 UTC 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

We have tried setting the router clock to a more current time, that didn't work - we have waited for several hours in hope that it would sync - that didn't work either.

Does anyone have any ideas?

Thank you for your help in advance.


Solution

  • The fix for us in this case was to set a ntp access-group peer access list.

    For example:

    ntp access-group peer 10
    
    access-list 10 remark NTP peers/servers we sync to/with
    access-list 10 permit 94.125.132.7
    access-list 10 deny any