This article mentions Doremi servers as an example, the same apply if you have issues with other servers.
When you have issues with NTP sync on Doremi servers, it's usually because NTP isn't working on the TMS (Doremi's usually sync time with the TMS). So log on to the TMS and run the command ntpq -np. This will show status of NTP sync on TMS. In the screenshot below it doesn't work. Stratum is 16 (should be 2-4), reach is 0 (no connection) and delay, offset, jitter is 0. Also look at the refid which is .INIT. where it should be WAN IP.
You can check configuration in /etc/ntp.conf. In this case the TMS is using ntp1.udnet.no and ntp2.udnet.no so we can check connectivity with netcat:
nc -vz ntp1.udnet.no 123
Which results in 'Connection refused".
As this is and Irish Odeon site, we can't have IT make any changes on the Cisco, so best solution is to route the ntp traffic through the Sonicwall:
route add -host 188.8.131.52 gw 10.53.34
route add -host 184.108.40.206 gw 10.53.34
If we now restart ntp it should start sync again.
Doremi servers should also start syncing again next time they try to sync with ntp, or you can log on and run /doremi/sbin/ntpwrap.sh which will try to sync with ntp server(s) configured in /doremi/etc/ntpservers.
You might get errors like "max adjustment reached". If so, you need to raise with Dolby to get a license to adjust the time up to 30 minutes.
Netcat does not work for UDP connections, unless you use the -u flag, and its configured for it on the server side as well.