diff -Naru old/ntp.conf new/ntp.conf
--- old/ntp.conf	2017-07-18 17:48:59.436221921 -0500
+++ new/ntp.conf	2017-07-18 18:00:54.392325489 -0500
@@ -1,17 +1,59 @@
-# This is the most basic ntp configuration file
 # The driftfile must remain in a place specific to this
 # machine - it records the machine specific clock error
-driftfile /var/lib/ntp/drift
+# Driftfile must be in a directory owned by ntp
+driftfile /var/lib/ntp/ntp.drift
+
+# The following code is for evaluating the timeserver.
+# Remove the # to activate the statistics
+# statsdir must start in column 1 for the initscript to
+# create the directory, in case it is volatile.
+#
+# statistics loopstats
+# statistics peerstats
+# statsdir /var/log/ntpstats
+# filegen peerstats file peerstats type day link enable
+# filegen loopstats file loopstats type day link enable
+
+# This is the US timeserver pool.  You should use a pool
+# close to your location.
+#pool us.pool.ntp.org iburst
+
 # This should be a server that is close (in IP terms)
 # to the machine.  Add other servers as required.
-# Unless you un-comment the line below ntpd will sync
-# only against the local system clock.
 #
 # server time.server.example.com
 #
+
+restrict default kod nomodify notrap nopeer noquery
+restrict -6 default kod nomodify notrap nopeer noquery
+restrict 127.0.0.1 mask 255.255.255.0
+restrict -6 ::1
+
+# GPS Serial data reference (NTP0)
+# This sets the GPS 50 milliseconds slower than the PPS.
+server 127.127.28.0 true
+fudge 127.127.28.0 time1 0.050 refid GPS
+
+# GPS PPS reference (NTP2)
+server 127.127.28.2 prefer true
+fudge 127.127.28.2 time1 0.000 refid PPS
+
+# orphanwait says that after 30 seconds, we can't find a server, we
+# will use the local clock.  This means ntp will hang for 30 seconds
+# during boot if we are not configured for an NTP server.
+tos orphanwait 30
+
 # Using local hardware clock as fallback
-# Disable this when using ntpd -q -g -x as ntpdate or it will sync to itself
-server 127.127.1.0
+
+# minpoll of 5 means 2^5 seconds or 32 seconds.  So first we wait 30
+# seconds if we can't get a response from another server, and then
+# if we don't get the response, we will use the local clock after
+# a 32 second poll interval.  So the NTP will hold up the boot for
+# 32 seconds if we don't have a good NTP server.
+server 127.127.1.0 minpoll 5
+# the local clock should always be set to a high stratum
+# (low priority), since it
+# is the system clock, which is not a good choice.
 fudge 127.127.1.0 stratum 14
 # Defining a default security setting
 restrict default