As you hopefully already know, you should use at least three different NTP servers to get your time. However, there might be situations in which you can configure only one single NTP server, either via static IP addresses or via an FQDN. To overcome this single point of failure you can use an external load balancing server such as F5 LTM (in HA of course) to forward your NTP queries to one of many NTP servers. Here are some hints:
