We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you two Citrix podcasts. Learn about 2020 trends and get answers to your biggest Citrix questions!Listen Now


Setting NTP commands on the core switch 6509

Ndehpanah asked
Medium Priority
Last Modified: 2012-05-06
We have 2 core switch in different location.In order to sysnc the time  on all the other switches we have got one TNP server from out side the organization.Then these core switches will get the time from the outside server and on the other switches we assign these core switches as ntp servers.but when I run Show ntp status on the core switch it shows:

Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 249.9982 Hz, precision is 2**24
reference time is CD30E8CB.0906E8E0 (14:36:43.035 AEST Mon Feb 2 2009)
clock offset is -13.2541 msec, root delay is 0.60 msec
root dispersion is 22.86 msec, peer dispersion is 9.60 msec

The configuration for ntp on one of the the core switches is :

ntp clock-period 17179989
ntp peer other core switch)
ntp server outside organiztion which the two core switches get the time from it)

I do not know what's wrong?May be I have done too simple config?
Watch Question

that message means that your routers are unsynchronized clocks.
so the router has valid time from ntp server, but is unable to sync with its peer.
So you can either remove ntp peer setting, or try to debug why clocks are not sync between two routers. possible reasons - second routed has different ntp settings: different time server, peer list is empty...

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts
I´d recommend when using NTP that you use only 1(2) server for all you equipment instead of having them read the time from different sources then you know that ntp is atleast in sync despite being wrong, and let that server get it from outside somewhere. You can always setup a secondary server using the prefer command.

This is my configuration that I use on all my 6500.
clock timezone CEST 1
clock summer-time CEST recurring last Sun Mar 2:00 last Sun Oct 3:00
ntp source Loopback0
ntp update-calendar
ntp server x.x.x.x prefer
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.