NTP POOL:
- By default, timesyncd uses the Google NTP servers
- time[1-4].google.com. They serve time that is not standards
- compliant, and can be up to .5s off. Google does not
- officially support these servers for the broader
- audience. Distributions and vendors really should not ship
- OSes or devices with these NTP servers configured. Instead,
- please register your own vendor pool at ntp.org and make it
- the built-in default by passing --with-ntp-servers= to
- configure. Registering vendor pools is free:
+ By default, timesyncd uses the Google Public NTP servers
+ time[1-4].google.com. They serve time that uses a leap second
+ smear, and can be up to .5s off from servers that use stepped
+ leap seconds.
- http://www.pool.ntp.org/en/vendors.html
+ https://developers.google.com/time/smear
+
+ If you prefer to use leap second steps, please register your own
+ vendor pool at ntp.org and make it the built-in default by
+ passing --with-ntp-servers= to configure. Registering vendor
+ pools is free:
- Again, if you ship your software or device with the default
- NTP servers, then you will get served wrong time, and will
- rely on services that might not be supported for long.
+ http://www.pool.ntp.org/en/vendors.html
PAM:
The default PAM config shipped by systemd is really bare bones.
false positives will be triggered by code which violates
some rules but is actually safe.
- Currently, systemd-timesyncd defaults to use the Google NTP
- servers if not specified otherwise at configure time. You
- really should not ship an OS or device with this default
- setting. See DISTRO_PORTING for details.
-
ENGINEERING AND CONSULTING SERVICES:
Kinvolk (https://kinvolk.io) offers professional engineering
and consulting services for systemd. Please contact Chris Kühl
AS_HELP_STRING([--with-ntp-servers=NTPSERVERS],
[space-separated list of default NTP servers]),
[NTP_SERVERS="$withval"],
- [NTP_SERVERS="time1.google.com time2.google.com time3.google.com time4.google.com"
- AC_MSG_WARN([*** Using Google NTP servers.
- Do not ship OSes or devices with these default settings.
- See DISTRO_PORTING for details!])])
+ [NTP_SERVERS="time1.google.com time2.google.com time3.google.com time4.google.com"])
AC_DEFINE_UNQUOTED(NTP_SERVERS, ["$NTP_SERVERS"], [Default NTP Servers])
AC_SUBST(NTP_SERVERS)