CUCM v15 Installation NTP inaccessible

[Pavan Manjunath]

Hi,

I'm trying to install CUCM v15.0.1.11901 from VMware ESXi v7.0.3. When i enter the NTP address it throws this error, "the ntp server(s) are mistyped, inaccessible or unreliable. Verify that valid NTP server names or ip addresses were entered, that are running NTPv4 at stratum 6 or less, and the port 123 is not blocked by the firewall" 

The same NTP address, I have given for CUCM v14.0.1.12900. The NTP address worked and installation setup successfully completed. 

I'm not sure why it's throwing inaccessible for v15. Need help to fix this.

I did checked with my local IT team and confirmed that NTP is accessible and no firewall block is found.

CUCM 15 Configuration Details

Guest OS: Red Hat Enterprise Linux 7 (64-bit)
Compatibility: ESXi 7.0 U2 virtual machine
VMWareTools: Yes
CPUs: 2
Memory: 10 GB
Hardisk 1: 110GB

[Roger Kallberg]

Time never allowed me to get back to you on this yesterday. This is how it looks when I create a new VM based on the OVA.

As you can tell it looks very different from what you shared. What type of ESXi are you using? I've added the same OVA that I used for reference.

[Pavan Manjunath]

@Roger Kallberg Thank you for your time and for providing the detailed steps. However, the UI appears to be entirely different from the one I’m using.
Below is the ESXi details

[Pavan Manjunath]

As a temporary workaround, I added the public NTP address (216.239.35.8), which allowed CUCM15 to be successfully installed. However, the local NTP address remains inaccessible. I would greatly appreciate your assistance in providing debugging steps to verify why our local NTP server is unsynchronized and showing as inaccessible.

[Brad Magnani]

Ultimately you'll need a packet capture as I mentioned earlier in this thread.  This document can get you going in the right direction with things to check/validate as well: https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/215537-network-time-protocol-ntp-on-cucm.html

[Pavan Manjunath]

@Brad Magnani Thank you for sharing the document. I have forwarded it to my IT team, and they are currently investigating

[Roger Kallberg]

It’s been mentioned before by others in this thread, but AFAIKT it has not been answered, so asking again. What type of server do you run the NTP system on?

[timuryuldashev]

Windows NTP is not supported