It is better to configure the chassis to use several time reference servers and then reboot. During startup, the chassis will set its initial system time from these servers and the NTP software will have a good time base from which to make minor adjustments. For best results, use at least four separate time servers that all reference different time sources themselves. This allows the NTP filtering and tracking algorithm to compare time information and get a more accurate “real” time. NTP does not work very well with less than three references as it has no way to weigh their accuracy against one another.