faraphel/chrony
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

doc: update chrony.conf man page for recent changes

Browse source
This commit is contained in:
Miroslav Lichvar 2017-08-02 16:48:33 +02:00
parent 9aac179367
commit d9f745fe70
1 changed files with 11 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
doc/chrony.conf.adoc
View file

@ -178,10 +178,9 @@ and the state might be dropped when there are too many clients (e.g.
by other clients that have the same IP address (e.g. computers behind NAT or
someone sending requests with a spoofed source address).
+
With longer polling intervals, it is recommended to combine the *xleave* option
with the *presend* option in order to shorten the interval in which the server
has to keep the state to be able to respond in the interleaved mode. The
shorter interval also improves accuracy of the measured offset and delay.
The *xleave* option can be combined with the *presend* option in order to
shorten the interval in which the server has to keep the state to be able to
respond in the interleaved mode.
*polltarget* _target_:::
Target number of measurements to use for the regression algorithm which
*chronyd* will try to maintain by adjusting the polling interval between
@ -1865,20 +1864,17 @@ be enabled by the *xleave* option in the <<server,*server*>> or the
This directive is supported on Linux 3.19 and newer. The NIC must support HW
timestamping, which can be verified with the *ethtool -T* command. The list of
capabilities should include _SOF_TIMESTAMPING_RAW_HARDWARE_,
_SOF_TIMESTAMPING_TX_HARDWARE_, _SOF_TIMESTAMPING_RX_HARDWARE_, and the filter
modes should include _HWTSTAMP_FILTER_ALL_ or _HWTSTAMP_FILTER_NTP_ALL_. When
_SOF_TIMESTAMPING_TX_HARDWARE_, _SOF_TIMESTAMPING_RX_HARDWARE_, and the receive
filters should include _HWTSTAMP_FILTER_ALL_ or _HWTSTAMP_FILTER_NTP_ALL_. When
*chronyd* is running, no other process (e.g. a PTP daemon) should be working
with the NIC clock.
with the NIC clock. HW timestamping of packets received from bridged and bonded
interfaces is supported on Linux 4.13 and newer.
+
If the kernel supports software timestamping, it will be enabled for all
interfaces. With both hardware and software timestamping there are some
limitations on which timestamps can be actually used, e.g. transmit
timestamping does not currently work with IPv6 packets using IP options and
hardware timestamping of packets received from bridges, bonds, and other
virtual interfaces, works only on Linux 4.13 and newer. The source of
timestamps (i.e. hardware, kernel, or daemon) is indicated in the
_measurements.log_ file if enabled by the <<log,*log measurements*>> directive,
and the <<chronyc.adoc#ntpdata,*ntpdata*>> report in *chronyc*.
interfaces. The source of timestamps (i.e. hardware, kernel, or daemon) is
indicated in the _measurements.log_ file if enabled by the <<log,*log
measurements*>> directive, and the <<chronyc.adoc#ntpdata,*ntpdata*>> report in
*chronyc*.
+
If the specified interface is _*_, *chronyd* will try to enable HW timestamping
on all available interfaces.