3Com Switch 8800 Configuration Guide Chapter 49 NTP Configuration49-1Chapter 49 NTP Configuration49.1 Brief Introduction to NTP49.1.1 NTP FunctionsAs the network topology gets more and more complex, it becomes important tosynchronize the clocks of the equipment on the whole network. Network Time Protocol(NTP) is the TCP/IP that advertises the accurate time throughout the network.NTP ensures the consistency of the following applications:z For the increment backup between the backup server and client, NTP ensures theclock synchronization between the two systems.z For multiple systems that coordinate to process a complex event, NTP ensuresthem to reference the same clock and guarantee the right order of the event.z Guarantee the normal operation of the inter-system (Remote Procedure Call).z Record for an application when a user logs in to a system, a file is modified, orsome other operation is performed.49.1.2 Basic Operating Principle of NTPThe following figure illustrates the basic operating principle of NTP:NetworkNetworkNTP packet 10:00:00amNetworkNetwork11:00:01amNTP packet 10:00:00am 11:00:01am 11:00:02amNTP packet 10:00:00amNTP Packet received at 10:00:031.2.3.4.LS_ALS_ALS_ALS_ALS_BLS_BLS_BLS_BFigure 49-1 Basic operating principle of NTPIn the figure above, Ethernet Switch A and Ethernet Switch B are connected throughthe Ethernet port. They have independent system clocks. Before implement automaticclock synchronization on both switches, we assume that:
