NTP Configuration

[Suresh Babu]

Hello All,

I have done the NTP configuration as below but my switch is not syncing with the server

Switch (Config)# NTP server x.x.x.x

Please let me know if anything am i missing here..

Rgds           

[JY109]

Is the configured ntp server require authentication?

Provide "show ntp status" for further troubleshoot

Sent from Cisco Technical Support Android App

[srikanth ath]

Hello suresh,

Kindly let us know where is the NTP server.

and provide below o/p

Router#

show ntp associations

Below is an example for NTP configuration on the core router and making lower end devices to synch with core router which acts as an NTP server.

Note: NTP server resides some-where outside/internet.

Initially make wan gateway router to synch up with the external NTP server as

Ntp server 129.89.29.191

Henceforth the router will synch its hardware time to NTP server.

To make below switches to synch up with the NTP server.

We have to issue

ntp server 8 …..> which tells the router to behave in as NTP server.

Then on the LAN distribution/core switches
ntp server 192.168.100.1 (the internal ip of the router interface)

Please rate the helpful posts.

Regards,

srikanth

[Giuseppe Larosa]

Hello Suresh,

as suggested by Jim post

show ntp association

sho ntp status

Be aware that NTP synchronization does not happen very quickly it may require some time.

Hope to help

Giuseppe

[skarthic]

Please provide the following outputs too

show run | in ntp

show clock

show ntp association detail

Thanks,

Karthic

[Suresh Babu]

Hi

Check the required outputs

switch#sh run | i ntp
ntp server 172.X.X.X

switch#sho clock
*23:28:04.135 UTC Tue Jun 8 1993

switch#sh ntp associations detail
172.X.X.X configured, insane, invalid, unsynced, stratum 16
ref ID 0.0.0.0, time 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)
our mode client, peer mode unspec, our poll intvl 64, peer poll intvl 16
root delay 0.00 msec, root disp 0.00, reach 0, sync dist 0.000
delay 0.00 msec, offset 0.0000 msec, dispersion 16000.00
precision 2**5, version 3
org time D40C3918.EC8B4394 (14:07:20.923 UTC Tue Sep 25 2012)
rcv time AFBF9ED2.8D415AD2 (23:27:14.551 UTC Tue Jun 8 1993)
xmt time AFBF9ED2.8CF0BB4D (23:27:14.550 UTC Tue Jun 8 1993)
filtdelay =     0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
filtoffset =    0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
filterror =  16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0

[cadet alain]

Hi,

as I explained set your clock manually to something near correct time before setting the clock to use NTP, reconfigure NTP and then the clock should sync with the NTP server.

Regards.

Alain.

Don't forget to rate helpful posts.

[Giuseppe Larosa]

Hello Alain,

you are right NTP specifications allows to sync when clock differences are within 128 seconds

Best Regards

Giuseppe

[johnlloyd_13]

hi alain,

this is great info and would help me to speed up NTP sync when setting up our routers! +5

[cadet alain]

Hi,

if your switch clock is too far away from time provided by the  NTP server it will take ages for the switch to be syncronized

So verify first that there is no too much difference between the times and if so change it to something near real time on the switch with set clock command.

Regards.

Alain

Don't forget to rate helpful posts.

[Suresh Babu]

Hi alain,

NTP server is colocated,

And instead of setting the clock manually, Shell we make that to happen automatically by syn with server

Rds

[cadet alain · Accepted solution]

Hi,

it will sync to NTP once the clock is near the clock of NTP server otherwise it will take ages.

Regards.

Alain

Don't forget to rate helpful posts.

[Suresh Babu]

Hi Alain,

Thanks for the guide..

Rgds