Ubuntu
ntp package

ntpd doesn't synchronize to local clock (ntpd 4.2.8p4/xenial)

Bug #1558125 reported by Jonathan Sylvain
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
ntp (Ubuntu)
Fix Released
High
Unassigned

Bug Description

Ubuntu 16.04 (Xenial Xerus development branch)
ntpd version: 1:4.2.8p4+dfsg-3ubuntu3
Source available at: http://packages.ubuntu.com/source/xenial/ntp

Using the local clock as a source for ntpd doesn't work anymore

This appears to have already been fixed in 4.2.8p5 as per the bug report referenced below
http://bugs.ntp.org/show_bug.cgi?id=2965

Sample config extract from /etc/ntp.conf:
server 127.127.1.0
fudge 127.127.1.0 stratum 3

Results from ntpq, we would expected the server to be reachable and synced :
# ntpd -p
     remote refid st t when poll reach delay offset jitter
==============================================================================
 LOCAL(0) .LOCL. 3 l - 64 0 0.000 0.000 0.000

# ntpq
ntpq> as

ind assid status conf reach auth condition last_event cnt
=============================================
  1 4979 8011 yes no none reject mobilize 1

Mathieu Trudel-Lapierre (cyphermox)
Changed in ntp (Ubuntu):
status: New → Triaged
importance: Undecided → High
tags: added: rls-x-incoming
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package ntp - 1:4.2.8p4+dfsg-3ubuntu4

---------------
ntp (1:4.2.8p4+dfsg-3ubuntu4) xenial; urgency=medium

  * d/p/fix_local_sync.patch: fix local clock sync (LP: #1558125).

 -- Pierre-André MOREY <email address hidden> Thu, 17 Mar 2016 10:42:44 +0100

Changed in ntp (Ubuntu):
status: Triaged → Fix Released
Revision history for this message
Jonathan Sylvain (jonathansylvain8) wrote :

Tested and confirmed it's working now.

There appears to be a behavioural change from 4.2.6 to 4.2.8 when using the local clock as a source.

In 4.2.6 the sync would be almost instantaneous while on 4.2.8 it will poll itself for a while before syncing as if it were an external resource.

I was able to overcome this delay by setting the local source as preferred

The new config in /etc/ntp.conf
server 127.127.1.0 prefer
fudge 127.127.1.0 stratum 3

To post a comment you must log in.
This report contains Public information  
Everyone can see this information.
Subscribing...

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.