To set up a local NTP server, these two lines are very important:
server 127.127.1.1
fudge 127.127.1.1 stratum 8 refid NIST
The description you seek is coming soon...my usual excuse...too lazy :(
server 127.127.1.1
fudge 127.127.1.1 stratum 8 refid NIST