Tasmar85, Alert Central uses three public ntp servers (see below). They are in the etc/ntp.conf file on the appliance. I haven't figured out how to modify this file yet, it is read-only on the appliance.
Here are the lines from the file:
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
Thank you for the information ScottRich. I don't think I would be able to write rules for these servers as they point to random set of servers that change every hour. I hope there is a way to edit the ntp.conf file because then I can add my internal ntp servers to the file so I don't have to have the application try to poll public ntp servers that change randomly.
Poke poke. Did anyone figure out how to edit /etc/ntp.conf? NTP is blocked by our firewall policy.