NAME

       timesyncd.conf, timesyncd.conf.d - Network Time Synchronization configuration files

SYNOPSIS

       /etc/systemd/timesyncd.conf

       /etc/systemd/timesyncd.conf.d/*.conf

       /run/systemd/timesyncd.conf.d/*.conf

       /usr/lib/systemd/timesyncd.conf.d/*.conf

DESCRIPTION

       These configuration files control NTP network time synchronization.

CONFIGURATION DIRECTORIES AND PRECEDENCE

       The default configuration is defined during compilation, so a configuration file is only
       needed when it is necessary to deviate from those defaults. By default, the configuration
       file in /etc/systemd/ contains commented out entries showing the defaults as a guide to
       the administrator. This file can be edited to create local overrides.

       When packages need to customize the configuration, they can install configuration snippets
       in /usr/lib/systemd/*.conf.d/. Files in /etc/ are reserved for the local administrator,
       who may use this logic to override the configuration files installed by vendor packages.
       The main configuration file is read before any of the configuration directories, and has
       the lowest precedence; entries in a file in any configuration directory override entries
       in the single configuration file. Files in the *.conf.d/ configuration subdirectories are
       sorted by their filename in lexicographic order, regardless of which of the subdirectories
       they reside in. When multiple files specify the same option, for options which accept just
       a single value, the entry in the file with the lexicographically latest name takes
       precedence. For options which accept a list of values, entries are collected as they occur
       in files sorted lexicographically. It is recommended to prefix all filenames in those
       subdirectories with a two-digit number and a dash, to simplify the ordering of the files.

       To disable a configuration file supplied by the vendor, the recommended way is to place a
       symlink to /dev/null in the configuration directory in /etc/, with the same filename as
       the vendor configuration file.

OPTIONS

       The following settings are configured in the "[Time]" section:

       NTP=
           A space-separated list of NTP server host names or IP addresses. During runtime this
           list is combined with any per-interface NTP servers acquired from systemd-
           networkd.service(8). systemd-timesyncd will contact all configured system or
           per-interface servers in turn until one is found that responds. When the empty string
           is assigned, the list of NTP servers is reset, and all assignments prior to this one
           will have no effect. This setting defaults to an empty list.

       FallbackNTP=
           A space-separated list of NTP server host names or IP addresses to be used as the
           fallback NTP servers. Any per-interface NTP servers obtained from systemd-
           networkd.service(8) take precedence over this setting, as do any servers set via NTP=
           above. This setting is hence only used if no other NTP server information is known.
           When the empty string is assigned, the list of NTP servers is reset, and all
           assignments prior to this one will have no effect. If this option is not given, a
           compiled-in list of NTP servers is used instead.

       RootDistanceMaxSec=
           Maximum acceptable root distance. Takes a time value (in seconds). Defaults to 5
           seconds.

       PollIntervalMinSec=, PollIntervalMaxSec=
           The minimum and maximum poll intervals for NTP messages. Each setting takes a time
           value (in seconds).  PollIntervalMinSec= must not be smaller than 16 seconds.
           PollIntervalMaxSec= must be larger than PollIntervalMinSec=.  PollIntervalMinSec=
           defaults to 32 seconds, and PollIntervalMaxSec= defaults to 2048 seconds.

SEE ALSO

       systemd(1), systemd-timesyncd.service(8), systemd-networkd.service(8)