Network Time Protocol overview
Network Time Protocol (NTP) maintains uniform time across all switches in a network. The NTP commands support the configuration of an external time server to maintain synchronization between all local clocks in a network.
To keep the time in your network current, it is recommended that each switch have its time synchronized with at least one external NTP server. External NTP servers should be synchronized among themselves in order to maintain fabric-wide time synchronization.
All switches in the fabric maintain the current clock server value in nonvolatile memory. By default, this value is the local clock server of the switch.