After configuring NTP, Not synched???....

[Soon Kwan Kwon]

Hello all,

I've configured a lot of APs.

Below design is each of it.

There are dozens of network design like upper.

Among them, one controller does not synchronize NTP in a design.

I really don't know why it was not operated properly.

> Controller can ping with Internet SW <-- Internet SW has NTP server.

> Also Internet SW can ping Controller....

Although ping ok, why didn't synchronize NTP server....??

Please see the upper captured picture....

How to fix it...?ㅠ_ㅠ

Regards,

SK.

[Leo Laohoo]

If the switch is Cisco, post the complete output to the command "sh ntp a".

[Soon Kwan Kwon]

Hello Leo,

This is output "sh ntp a" in Controller.

SW#show ntp associations

address ref clock st when poll reach delay offset disp
~203.248.240.140 .INIT. 16 - 1024 0 0.000 0.000 15937.
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured
SW#

Please see the output...!

Thank you.

[Leo Laohoo]

~203.248.240.140 .INIT. 16 - 1024 0 0.000 0.000 15937.

The WLC is behaving correctly.  Notice at the left-hand side there is only the "~".  If the NTP is synchronized to a valid time source the left-hand column should start with a "*".  

So this means that the switch, where the WLC is attempting to synchronize the time source, is NOT in synchronize with a valid time source.  The WLC is, most likely, have detected that the time from the switch is invalid.

[Soon Kwan Kwon]

Hmmm...

Maybe do you know why the WLC is getting invalid time.. even though the SW has correct NTP server IP...

Is it possible device fault?

-----------------------------------------

SW2#show ntp a

address ref clock st when poll reach delay offset disp
*~203.248.240.140 204.123.2.5 2 495 1024 377 7.014 -5.883 0.157
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured

It is another sw I have... but it's working properly...

(Its sw is another network design's)

-----------------------------------------

Regards,

SK.

[Leo Laohoo]

Could be a FW rule?

[Soon Kwan Kwon]

There aren't FW rule.

[Leo Laohoo]

Hold on ... I saw an event once when the switch, a 6807-X, would keep loosing sync with a known NTP time source.  The cause of the issue was an IOS bug.

[Soon Kwan Kwon]

AH? Leo, where is the switch, 6807-X ?

Why did you judge the cause of the issue was IOS bug ?...

[Soon Kwan Kwon]

Leo,,

Like you said, IOS bug is correct.

Should I update IOS version...?!

[Soon Kwan Kwon]

Why did you say "Could be a FW rule?"

Actually I don't understand clearly...Leo