Description

NTP synchronization fails with refid .INIT.

Symptoms

user@router> show ntp associations
   remote         refid           st t when poll reach   delay   offset  jitter
===============================================================================
 10.1.1.10        .INIT.          16 -    -  512    0    0.000    0.000 4000.00
 10.1.1.11        .INIT.          16 -    -  512    0    0.000    0.000 4000.00

user@router> show ntp status
status=c011 sync_alarm, sync_unspec, 1 event, event_restart,
version="ntpd 4.2.0-a Thu Jan 26 00:34:26  2023 (1)", processor="amd64",
system="FreeBSDJNPR-12.1-20230120.6bab16a_buil", leap=11, stratum=16,
precision=-23, rootdelay=0.000, rootdispersion=0.075, peer=0,
refid=INIT, reftime=00000000.00000000  Wed, Feb  6 2036 22:28:16.000,
poll=4, clock=e9f02ff0.ed03a881  Thu, May 16 2024  0:10:40.925, state=1,
offset=0.000, frequency=68.364, jitter=0.000, stability=0.000

Solution

The refid code .INIT. indicates the association has not yet synchronized for the first time, probably the router does not receive NTP packets from the server.
  1. Check lo0 filter, make sure there is no discard action matching the NTP server's IP address and UDP port 123.
  2. Check the connectivity with NTP server.
  3. Monitor traffic matching the NTP server's IP and UDP port 123, to confirm if any NTP packets arriving the router. 
As the sample command to monitor NTP traffic below, can see there is no NTP packet received from NTP server. 
user@router> monitor traffic interface fxp0 size 1500 detail no-resolve matching "host 10.1.1.10"
Address resolution is OFF.
Listening on fxp0, capture size 1500 bytes
00:15:41.315584 Out IP (tos 0x10, ttl  64, id 54645, offset 0, flags [none], proto: UDP (17), length: 76) 10.0.0.1.123 > 10.1.1.10.123: NTPv4, length 48
    Client, Leap indicator: clock unsynchronized (192), Stratum 0, poll 6s, precision -23
    Root Delay: 0.000000, Root dispersion: 0.001159, Reference-ID: (unspec)
      Reference Timestamp:  0.000000000
      Originator Timestamp: 0.000000000
      Receive Timestamp:    0.000000000
      Transmit Timestamp:   3924832541.315571537
        Originator - Receive Timestamp:  0.000000000
        Originator - Transmit Timestamp: 3924832541.315571537
00:15:43.315583 Out IP (tos 0x10, ttl  64, id 54834, offset 0, flags [none], proto: UDP (17), length: 76) 10.0.0.1.123 > 10.1.1.10.123: NTPv4, length 48
    Client, Leap indicator: clock unsynchronized (192), Stratum 0, poll 6s, precision -23
    Root Delay: 0.000000, Root dispersion: 0.001190, Reference-ID: (unspec)
      Reference Timestamp:  0.000000000
      Originator Timestamp: 0.000000000
      Receive Timestamp:    0.000000000
      Transmit Timestamp:   3924832543.315568666
        Originator - Receive Timestamp:  0.000000000
        Originator - Transmit Timestamp: 3924832543.315568666
00:15:45.315583 Out IP (tos 0x10, ttl  64, id 55025, offset 0, flags [none], proto: UDP (17), length: 76) 10.0.0.1.123 > 10.1.1.10.123: NTPv4, length 48
    Client, Leap indicator: clock unsynchronized (192), Stratum 0, poll 6s, precision -23
    Root Delay: 0.000000, Root dispersion: 0.001220, Reference-ID: (unspec)
      Reference Timestamp:  0.000000000
      Originator Timestamp: 0.000000000
      Receive Timestamp:    0.000000000
      Transmit Timestamp:   3924832545.315569047
        Originator - Receive Timestamp:  0.000000000
        Originator - Transmit Timestamp: 3924832545.315569047

Modification History

2024-05-16 : Article Created