From 8c0ee9c175bab488a40c81c0ee6ee105576f3c0d Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Wed, 4 Mar 2020 09:10:54 +0100 Subject: [PATCH] doc: list unsupported options in peer directive --- doc/chrony.conf.adoc | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/doc/chrony.conf.adoc b/doc/chrony.conf.adoc index 0f6a281..5962c66 100644 --- a/doc/chrony.conf.adoc +++ b/doc/chrony.conf.adoc @@ -194,14 +194,13 @@ authenticated source to be safely combined with unauthenticated sources in order to improve the accuracy of the clock. They can be selected and used for synchronisation only if they agree with the trusted and required source. *xleave*::: -This option enables an interleaved mode which allows the server or the peer to +This option enables an interleaved mode which enables the server to send transmit timestamps captured after the actual transmission (e.g. when the -server or the peer is running *chronyd* with software (kernel) or hardware +server is running *chronyd* with software (kernel) or hardware timestamping). This can significantly improve the accuracy of the measurements. + The interleaved mode is compatible with servers that support only the basic -mode, but peers must both support and have enabled the interleaved mode, -otherwise the synchronisation will work only in one direction. Note that even +mode. Note that even servers that support the interleaved mode might respond in the basic mode as the interleaved mode requires the servers to keep some state for each client and the state might be dropped when there are too many clients (e.g. @@ -243,8 +242,8 @@ when the polling interval is 512 seconds or more, an extra NTP client packet will be sent to the server a short time (2 seconds) before making the actual measurement. + -The *presend* option cannot be used in the *peer* directive. If it is used -with the *xleave* option, *chronyd* will send two extra packets instead of one. +If the *presend* option is used together with the *xleave* option, *chronyd* +will send two extra packets instead of one. *minstratum* _stratum_::: When the synchronisation source is selected from available sources, sources with lower stratum are normally slightly preferred. This option can be used to @@ -297,6 +296,12 @@ is mainly useful when the NTP implementation of the peer (e.g. *ntpd*) supports ephemeral symmetric associations and does not need to be configured with an address of this host. *chronyd* does not support ephemeral associations. + +The following options of the *server* directive do not work in the *peer* +directive: *iburst*, *burst*, *presend*. ++ +When using the *xleave* option, both peers must support and have enabled the +interleaved mode, otherwise the synchronisation will work in one direction +only. When a key is specified by the *key* option to enable authentication, both peers must use the same key and the same key number. +