Server mode makes a Cisco IOS device provide NTP time from its own software clock without acting as a client of an external NTP server. The ntp master command enables this mode; ntp server instead creates client/server mode, where the device learns time externally and serves it onward. section 2.3.2 section 2.4
Configure and verify server mode with these operational points:
- Enter ntp master to use the device’s own clock as the NTP reference; the default local-clock server stratum is 8. section 2.4
- Optionally specify a stratum, such as ntp master 5, to change the advertised hierarchy position. section 2.3.2
- Use a loopback address as the server address for clients when a stable address independent of physical-port status is required. section 2.3.2
- Check time sources with show ntp associations and the device’s hierarchy position with show ntp status. section 2.4
Configure a primary NTP server
R1(config)# ntp master 5 R1(config)# do show ntp associations ~127.127.1.1 .LOCL. 4 The local clock appears as 127.127.1.1 with a stratum of 4 when the configured master stratum is 5.
