To configure a client to utilise NTP, in global configuration mode use the following command:
ntp server x.x.x.x
Replace x.x.x.x with the IP address of the NTP server. There are additional keywords
source. Prefer will set the server as a preferred NTP source. Source is to set the source interface where the NTP packets will be sent from.
The status of the NTP service can be viewed with the command
show ntp status
The status command can show whether the hardware close is synchronised to the software close, the stratum reference of the local device and the reference clock identifier.
The frequency and precision of the clock, NTP uptime, reference, clock offset and delay, root dispersion, and polling interval are all displayed with this command too.
Once a Cisco device has had client configuration added, it can also act as an NTP server to other devices. Set the stratum number of the Cisco device with the following command:
ntp master <stratum-number>