Attachment 301339 Details for Bug 229217 – ntp.conf using tos orphan and tos minsane statements.

ntp.conf using tos orphan and tos minsane statements.

ntp.conf-standard (text/plain), 3.59 KB, created by archimerged Ark submedes on 2008-04-04 20:50:56 UTC

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Creator: archimerged Ark submedes

Created: 2008-04-04 20:50:56 UTC

Size: 3.59 KB

patch

obsolete

># For more information about this file, see the man pages ntp.conf(5),
># ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5).  For
># more complete information, see /usr/share/doc/ntp*/index.html.
>
>driftfile /var/lib/ntp/drift
>
># Permit time synchronization with our time source, but do not
># permit the source to query or modify the service on this system.
>restrict default kod nomodify notrap nopeer noquery
>
># Permit all access over the loopback interface.  This could
># be tightened as well, but to do so would affect some of
># the administrative functions.
>restrict 127.0.0.1 
>
># Hosts on local network are less restricted.
>restrict 192.168.197.0 mask 255.255.255.0 nomodify notrap
>
># From /usr/share/doc/ntp-4.2.4p4/manyopt.html:
># Sometimes it is necessary to operate an NTP subnet in isolation,
># because a local reference clock is unavailable or connectivity to
># the Internet is not provided. In such cases it may be necessary that
># the subnet servers and clients remain synchronized to a common
># timescale, not necessarily the UTC timescale. Previously, this
># function was provided by the local clock driver, which could be
># configured for a server that could be reached, directly or
># indirectly from all other servers and clients in the subnet.
>
># There are many disadvantages using the local clock driver: multiple
># source redundancy is not possible and the subnet is vulnerable to
># single-point failures. Orphan mode is intended to replace the need
># for the local clock driver. It operates in subnet configurations in
># all modes, including broadcast, and multiple servers and clients and
># handles seamless switching as primary sources fail and recover.
>
># A server or client is enabled for orphan mode using the [ 'tos'
># 'orphan' stratum ] command, where stratum is some stratum less than
># 16 and greater than any anticipated stratum that might occur with
># ordinary Internet servers. This is the same consideration that
># guides the local clock driver stratum.
>
># As long as the stratum of any orphan is less than the orphan
># stratum, the servers and clients operate in the normal way. However,
># if the stratum equals or exceeds this stratum, the server or client
># is considered an orphan. If under these conditions a host has no
># sources of the same or lower stratum, it is designated an orphan
># parent; otherwise, it is considered an orphan child. Orphan parents
># show offset zero, root delay zero and reference ID 127.0.0.1, which
># of course is the Unix loopback address. Orphan children show the
># mitigated offset of their servers, root delay randomized over a
># moderate range and reference ID of their system peer. An important
># distinction is that the entire subnet operates at the same orphan
># stratum and that the order of preference is the root delay, not the
># stratum and root distance as usual.
>
># For the most flexible and reliable operation, all servers and
># clients in the subnet should include the 'orphan' command in
># the configuration file and with the same orphan stratum. This
># provides mutual redundancy and diversity for all NTP modes of
># operation, including broadcast.
>tos orphan 5
>
># [ 'tos' 'minsane' number ] specifies the minimum number of
># candidates available to the clock selection algorithm in order to
># produce one or more truechimers for the clustering algorithm. If
># fewer than this number are available, the clock is undisciplined and
># allowed to run free. The default is 1 for legacy purposes. However,
># according to principles of Byzantine agreement, minsane should be at
># least 4 in order to detect and discard a single falseticker.
>tos minsane 4
>
>includefile /etc/ntp/ntpservers

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Attachments on bug 229217: 296601 | 301339 | 301340 | 301342 | 301344