Whats an Appropriate NTP Architecture for PoE Clocks?
As a general rule, it’s wise to have an internal time server on your network to support your PoE clocks. This is particularly true if you are deploying a number of PoE clocks. Here are some reasons why this is important: • If you have a large number of clocks independently referencing the same external time server, you may possibly run afoul of the external time server’s network access policy (by accessing the time server more frequently than its open access policy allows). • An internal time server reduces Internet traffic, and helps secure timekeeping on the network. Secure timekeeping on the network is important because opening your network to NTP (port 123) traffic allows for the possibility of these types of hacker intrusions: • Sending too much data in the NTP packet, thus causing the NTP service to become overloaded and resulting in a denial of time services attack. • Sending specially constructed packets that essentially “take over” machines within your network (by using the sa
