Good mornign Mr. Dicko. See, when crested service NTP on FreePBX web GUI as BILLSIMON suggested, this is what now sends result of “tcpdump -nnvv port 123”
09:34:57.358440 IP (tos 0x0, ttl 64, id 901, offset 0, flags [none], proto UDP (17), length 76)
172.16.26.188.1044 > 172.16.26.6.123: [udp sum ok] NTPv3, length 48
Client, Leap indicator: (0), Stratum 0 (unspecified), poll 8 (256s), precision 0
Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec)
Reference Timestamp: 0.000000000
Originator Timestamp: 0.000000000
Receive Timestamp: 0.000000000
Transmit Timestamp: 0.000000000
Originator - Receive Timestamp: 0.000000000
Originator - Transmit Timestamp: 0.000000000
09:34:57.358588 IP (tos 0x0, ttl 64, id 6573, offset 0, flags [DF], proto UDP (17), length 76)
172.16.26.6.123 > 172.16.26.188.1044: [udp sum ok] NTPv3, length 48
Server, Leap indicator: clock unsynchronized (192), Stratum 0 (unspecified), poll 8 (256s), precision -21
Root Delay: 1.000000, Root dispersion: 1.000000, Reference-ID: (unspec)
Reference Timestamp: 0.000000000
Originator Timestamp: 0.000000000
Receive Timestamp: 3785736897.358440813 (2019/12/19 09:34:57)
Transmit Timestamp: 3785736897.358557045 (2019/12/19 09:34:57)
Originator - Receive Timestamp: 3785736897.358440813 (2019/12/19 09:34:57)
Originator - Transmit Timestamp: 3785736897.358557045 (2019/12/19 09:34:57)
09:34:57.686016 IP (tos 0x0, ttl 64, id 1100, offset 0, flags [none], proto UDP (17), length 76)
172.16.26.190.1044 > 172.16.26.6.123: [udp sum ok] NTPv3, length 48
Client, Leap indicator: (0), Stratum 0 (unspecified), poll 8 (256s), precision 0
Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec)
Reference Timestamp: 0.000000000
Originator Timestamp: 0.000000000
Receive Timestamp: 0.000000000
Transmit Timestamp: 0.000000000
Originator - Receive Timestamp: 0.000000000
Originator - Transmit Timestamp: 0.000000000
09:34:57.686148 IP (tos 0x0, ttl 64, id 62458, offset 0, flags [DF], proto UDP (17), length 76)
172.16.26.6.123 > 172.16.26.190.1044: [udp sum ok] NTPv3, length 48
Server, Leap indicator: clock unsynchronized (192), Stratum 0 (unspecified), poll 8 (256s), precision -21
Root Delay: 1.000000, Root dispersion: 1.000000, Reference-ID: (unspec)
Reference Timestamp: 0.000000000
Originator Timestamp: 0.000000000
Receive Timestamp: 3785736897.686016607 (2019/12/19 09:34:57)
Transmit Timestamp: 3785736897.686121651 (2019/12/19 09:34:57)
Originator - Receive Timestamp: 3785736897.686016607 (2019/12/19 09:34:57)
Originator - Transmit Timestamp: 3785736897.686121651 (2019/12/19 09:34:57)
The “Receive Timestamp”, “Transmit Timestamp”, “Originator - Receive Timestamp” and “Originator - Transmit Timestamp” are getting some data, is it good???