If NTP is unable to synchronise on a Cisco switch or router you may resolve the root cause and the device will still not be synchronised when we check. This is because the device will wait until the next polling interval to try again. Normally we can wait however in instances where we need to update a number of devices this process can be time consuming.
Device# Show ntp associations address ref clock st when poll reach delay offset disp ~126.96.36.199 .INIT. 16 - 64 0 0.000 0.000 15937. sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured
To force the sync simply remove the NTP configuration for that peer and re-add it. On the addition of the peer the initial sync is immediate.
Device#conf t Device(config)#no ntp server 188.8.131.52 Device(config)#ntp server 184.108.40.206
And now when we check it will have immediately been synchronised.
address ref clock st when poll reach delay offset disp +~220.127.116.11 18.104.22.168 2 31 64 1 15.958 3.940 188.52