# local
# if the satellites are lost, set the stratum to 10
server 127.127.1.0
fudge 127.127.1.0 stratum 10

# GPS 
# SHM Reference Clock (driver 28 - 127.127.28.0)
# flag1 1 - Skip the difference limit check if set. Useful for systems where the RTC backup cannot keep the time over long periods without power and the SHM clock must be able to force long-distance initial jumps. Check the difference limit if cleared (default).
# refid string - Specifies the driver reference identifier, an ASCII string from one to four characters, with default SHM.
server 127.127.28.0 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.0 flag1 1 refid GPS 

# GPS PPS reference
# PPS is not used
#server 127.127.28.1 minpoll 4 maxpoll 4
#fudge 127.127.28.1 refid PPS

# file with system clock offset
driftfile /var/lib/ntp/ntp.drift

# deny access to the ntp server
restrict default ignore

# allow access to itself
restrict 127.0.0.1 

#disable auth
#logfile /var/log/ntp/messages
logfile /home/ntp/messages