About the time synchronization of APs belonging to Catalyst9800

[RYXYLISHX]

Hello.

If the NTP server address is not set in the AP Join Profile for an AP that belongs to Catalyst9800, will the AP's time be synchronized with Catalyst9800?
Or will the AP continue to be out of sync?

Thanks.

[Scott Fella]

In all my years working on Cisco wireless, I have never seen an ap sync time with a controller if NTP was not set.  I don't see why you wouldn't set it if your controller and other network devices are pointing already to an ntp source.  You should be able to test that.  Reboot an ap and then see if the time on the ap is off.... I would think so.

[Rich R · Accepted solution]

Not so @Scott Fella - the AP syncs to the WLC time over CAPWAP when it joins the WLC so the AP will always have the correct time (within the accuracy of the CAPWAP time sync).  That's how it is able to evaluate certificate validity etc regardless of NTP availability.

But NTP provides a more accurate/precise time sync - ideally to a local NTP time source rather than the WLC which could be remote to the AP.

From CAPWAP discovery response:

[RYXYLISHX]

Thank you for your reply.

I understand now that the AP syncs its time with the WLC via CAPWAP.
The capture data you shared was super helpful in confirming that.

Thanks again for your help!

[Rich R]

No problem, you're welcome