CUCM phones randomly went down

[Amafsha1]

hello, we had a bunch of phones just randomly go down today then they all came back up 20 min later.  This was when not much people were around.  Does anyone know where in RTMT I can go to tshoot an issue like this?

[Amafsha1]

I also noticed that right before the phones went down, we recieved an "NTP is not synchronized with any of the external NTP servers.." log.  Could this possibly bring phones down?

[Aeby Vinod]

To troubleshoot this, Pull the following logs:

Callmanager traces.
Event viewer app and sys logs.
Console logs from a few Phones which went through the outage.

Also I cant think of a way why NTP being un-synchronizing could have been the cause for the reset, but the reason behind NTP un-synchronizing can be a root cause, maybe the network connection from the CUCM and the NTP server/Phones might have gone down, there can be a variety of factors on the network which would have caused this, but from the logs mentioned above you can at the least get a direction as to where to look at.

Please rate if you find this helpful.

Regards,
Aeby

[Amafsha1]

Thanks for the response. 30 seconds before the NTP log, I realized that there was a log that came in saying "duplicate IP address detected based on ethernet header" with some MAC address it listed that was a desktop machine.  I think that was the problem.  How do you view callmanager traces like you mentioned?  I was able to find the other 2, but not call manager traces.