diff --git a/2.Common_services/2.NTP/ntp.conf b/2.Common_services/2.NTP/ntp.conf
index e3def2a0f04e0095680384d273c3ce52f5e7b5e1..0940553415b0b9d0516f6d71963bc1dbaf388099 100644
--- a/2.Common_services/2.NTP/ntp.conf
+++ b/2.Common_services/2.NTP/ntp.conf
@@ -2,6 +2,8 @@
 
 driftfile /var/lib/ntp/ntp.drift
 
+# Leap seconds definition provided by tzdata
+leapfile /usr/share/zoneinfo/leap-seconds.list
 
 # Enable this if you want statistics to be logged.
 #statsdir /var/log/ntpstats/
@@ -13,6 +15,18 @@ filegen clockstats file clockstats type day enable
 
 # Specify one or more NTP servers.
 {{ servers }}
+
+# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
+# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
+# more information.
+#pool 0.ubuntu.pool.ntp.org iburst
+#pool 1.ubuntu.pool.ntp.org iburst
+#pool 2.ubuntu.pool.ntp.org iburst
+#pool 3.ubuntu.pool.ntp.org iburst
+
+# Use Ubuntu's ntp server as a fallback.
+#pool ntp.ubuntu.com
+
 # Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
 # details.  The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
 # might also be helpful.
@@ -22,13 +36,16 @@ filegen clockstats file clockstats type day enable
 # up blocking replies from your own upstream servers.
 
 # By default, exchange time with everybody, but don't allow configuration.
-restrict -4 default kod notrap nomodify nopeer noquery
-restrict -6 default kod notrap nomodify nopeer noquery
+restrict -4 default kod notrap nomodify nopeer noquery limited
+restrict -6 default kod notrap nomodify nopeer noquery limited
 
 # Local users may interrogate the ntp server more closely.
 restrict 127.0.0.1
 restrict ::1
 
+# Needed for adding pool entries
+restrict source notrap nomodify noquery
+
 # Clients from this (example!) subnet have unlimited access, but only if
 # cryptographically authenticated.
 #restrict 192.168.123.0 mask 255.255.255.0 notrust
@@ -42,3 +59,12 @@ restrict ::1
 # next lines.  Please do this only if you trust everybody on the network!
 #disable auth
 #broadcastclient
+
+#Changes recquired to use pps synchonisation as explained in documentation:
+#http://www.ntp.org/ntpfaq/NTP-s-config-adv.htm#AEN3918
+
+#server 127.127.8.1 mode 135 prefer    # Meinberg GPS167 with PPS
+#fudge 127.127.8.1 time1 0.0042        # relative to PPS for my hardware
+
+#server 127.127.22.1                   # ATOM(PPS)
+#fudge 127.127.22.1 flag3 1            # enable PPS API