doc: list unsupported options in peer directive

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Miroslav Lichvar 2020-03-04 09:10:54 +01:00
parent f20fabdbf4
commit 8c0ee9c175

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@ -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 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. synchronisation only if they agree with the trusted and required source.
*xleave*::: *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 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. timestamping). This can significantly improve the accuracy of the measurements.
+ +
The interleaved mode is compatible with servers that support only the basic The interleaved mode is compatible with servers that support only the basic
mode, but peers must both support and have enabled the interleaved mode, mode. Note that even
otherwise the synchronisation will work only in one direction. Note that even
servers that support the interleaved mode might respond in the basic mode as 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 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. 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 will be sent to the server a short time (2 seconds) before making the actual
measurement. measurement.
+ +
The *presend* option cannot be used in the *peer* directive. If it is used If the *presend* option is used together with the *xleave* option, *chronyd*
with the *xleave* option, *chronyd* will send two extra packets instead of one. will send two extra packets instead of one.
*minstratum* _stratum_::: *minstratum* _stratum_:::
When the synchronisation source is selected from available sources, sources When the synchronisation source is selected from available sources, sources
with lower stratum are normally slightly preferred. This option can be used to 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 ephemeral symmetric associations and does not need to be configured with an
address of this host. *chronyd* does not support ephemeral associations. 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 When a key is specified by the *key* option to enable authentication, both
peers must use the same key and the same key number. peers must use the same key and the same key number.
+ +