From b33b68235630d0de3b2d7f95b7554b5b90250a7f Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Fri, 22 Jun 2018 12:09:31 +0200 Subject: [PATCH] doc: update chrony.conf man page for recent changes --- doc/chrony.conf.adoc | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/doc/chrony.conf.adoc b/doc/chrony.conf.adoc index e3b0110..da86723 100644 --- a/doc/chrony.conf.adoc +++ b/doc/chrony.conf.adoc @@ -72,24 +72,27 @@ polling interval should not drop below 32 seconds. The default is 6 (64 seconds), the minimum is -4 (1/16th of a second), and the maximum is 24 (6 months). Note that intervals shorter than 6 (64 seconds) should generally not be used with public servers on the Internet, because it might be considered -abuse. +abuse. A sub-second interval will be enabled only when the server is reachable +and the round-trip delay is shorter than 10 milliseconds, i.e. the server +should be in a local network. *maxpoll* _poll_::: This option specifies the maximum interval between requests sent to the server as a power of 2 in seconds. For example, *maxpoll 9* indicates that the polling interval should stay at or below 9 (512 seconds). The default is 10 (1024 -seconds), the minimum is 0 (1 second), and the maximum is 24 (6 months). +seconds), the minimum is -4 (1/16th of a second), and the maximum is 24 (6 +months). *iburst*::: With this option, the interval between the first four requests sent to the -server will be 2 seconds instead of the interval specified by the *minpoll* -option, which allows *chronyd* to make the first update of the clock shortly -after start. +server will be 2 seconds or less instead of the interval specified by the +*minpoll* option, which allows *chronyd* to make the first update of the clock +shortly after start. *burst*::: With this option, *chronyd* will shorten the interval between up to four -requests to 2 seconds when it cannot get a good measurement from the server. -The number of requests in the burst is limited by the current polling interval -to keep the average interval at or above the minimum interval, i.e. the current -interval needs to be at least two times longer than the minimum interval in -order to allow a burst with two requests. +requests to 2 seconds or less when it cannot get a good measurement from the +server. The number of requests in the burst is limited by the current polling +interval to keep the average interval at or above the minimum interval, i.e. +the current interval needs to be at least two times longer than the minimum +interval in order to allow a burst with two requests. *key* _ID_::: The NTP protocol supports a message authentication code (MAC) to prevent computers having their system time upset by rogue packets being sent to them.