I wish to understand the scenario in which we have defined only remote servers in the /etc/ntp.conf file and we have not set the LOCAL ntp server (127.0.0.1) options.
What happens in case of a network partition, where the server looses its communication with the remote servers? Will the ntp service go into error state? Given that no server is available not for time sync.
After losing network connectivity to NTP servers, ntpd or chrony will continue to run. Clock discipline will continue based on known trends. Reach statuses reported for each peer will decrease when packets do not arrive on schedule.
How fast this diverges from stratum one mostly depends on if drift was recorded from earlier NTP packets. Paul Gear's local only experiment shows a server with only a drift file slowly deviating from a host with enough NTP sources. Remove the drift file, and the much worse deviation shows how bad the server's local clock is.
Do not use undisciplined local clock, aka refid LOCL, aka 127.127.1.0. Not appropriate for a client ntpd that is not serving time. For running your own NTP service, multiple peer servers at the same stratum, orphan mode is better.
