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Sample config for peering multicast NTP servers
# /etc/ntp.conf for multicast servers
# Kenneth Finnegan, 2014
# Logging of stats, etc
driftfile /var/lib/ntp/ntp.drift
statsdir /var/log/ntpstats/
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
# Pull multiple ntp.org pool NTP servers as the basis for local time
server 0.ubuntu.pool.ntp.org
server 1.ubuntu.pool.ntp.org
server 2.ubuntu.pool.ntp.org
server 3.ubuntu.pool.ntp.org
# Access control configuration
# For multicast, MAKE SURE TO REMOVE nopeer
restrict -4 default kod notrap nomodify noquery
restrict -6 default kod notrap nomodify noquery
# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1
# Beacon to this locally admin address
# Note that ttl is an index into the ttl array, not an actual ttl value
# By default, it seems to be 0, which maps to 1, which doesn't cross subnets
# ttl 7 sets it to the maximum value of 224, since the default array is multiples of 32
broadcast 239.192.1.1 ttl 7
# Disable authentication and listen for the other peer servers
disable auth
multicastclient 239.192.1.1
kenneth@KWF3:~$ ntpq -pn -c rv
remote refid st t when poll reach delay offset jitter
==============================================================================
-10.44.1.1 132.163.4.102 3 u 521 1024 377 0.302 -9.587 5.805
-198.199.111.124 216.218.192.202 2 u 34 1024 377 24.987 13.977 1.416
*166.70.136.41 .GPS. 1 u 773 1024 377 77.533 -5.500 3.148
-2001:4f8:fff7:1 216.218.254.202 2 u 1014 1024 377 24.295 11.447 1.555
+64.246.132.14 .CDMA. 1 u 253 1024 377 97.612 9.846 0.523
+91.189.89.199 193.79.237.14 2 u 52 1024 377 152.725 8.163 1.508
239.192.1.1 .MCST. 16 u - 64 0 0.000 0.000 0.002
-10.44.1.188 10.44.1.13 3 m 19 64 376 0.760 -4.619 0.013
-10.44.1.142 10.44.1.13 3 m 23 64 377 0.092 -4.532 0.044
associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync,
version="ntpd 4.2.6p3@1.2290-o Tue Jun 5 20:12:08 UTC 2012 (1)",
processor="x86_64", system="Linux/3.2.0-58-generic", leap=00, stratum=2,
precision=-19, rootdelay=77.533, rootdisp=47.586, refid=166.70.136.41,
reftime=d67d7a9a.b7d316b7 Sun, Jan 12 2014 12:33:30.718,
clock=d67d7d9f.b5ac8204 Sun, Jan 12 2014 12:46:23.709, peer=36371,
tc=10, mintc=3, offset=2.949, frequency=-56.460, sys_jitter=12.017,
clk_jitter=1.622, clk_wander=0.241
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