diff options
Diffstat (limited to 'examples/chrony.conf.example3')
| -rw-r--r-- | examples/chrony.conf.example3 | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/examples/chrony.conf.example3 b/examples/chrony.conf.example3 new file mode 100644 index 0000000..8d895d0 --- /dev/null +++ b/examples/chrony.conf.example3 @@ -0,0 +1,334 @@ +####################################################################### +# +# This is an example chrony configuration file. You should copy it to +# /etc/chrony.conf after uncommenting and editing the options that you +# want to enable. The more obscure options are not included. Refer +# to the documentation for these. +# +####################################################################### +### COMMENTS +# Any of the following lines are comments (you have a choice of +# comment start character): +# a comment +% a comment +! a comment +; a comment +# +# Below, the '!' form is used for lines that you might want to +# uncomment and edit to make your own chrony.conf file. +# +####################################################################### +####################################################################### +### SPECIFY YOUR NTP SERVERS +# Most computers using chrony will send measurement requests to one or +# more 'NTP servers'. You will probably find that your Internet Service +# Provider or company have one or more NTP servers that you can specify. +# Failing that, there are a lot of public NTP servers. There is a list +# you can access at http://support.ntp.org/bin/view/Servers/WebHome or +# you can use servers from the pool.ntp.org project. + +! server ntp1.example.net iburst +! server ntp2.example.net iburst +! server ntp3.example.net iburst + +! pool pool.ntp.org iburst + +####################################################################### +### AVOIDING POTENTIALLY BOGUS CHANGES TO YOUR CLOCK +# +# To avoid changes being made to your computer's gain/loss compensation +# when the measurement history is too erratic, you might want to enable +# one of the following lines. The first seems good with servers on the +# Internet, the second seems OK for a LAN environment. + +! maxupdateskew 100 +! maxupdateskew 5 + +# If you want to increase the minimum number of selectable sources +# required to update the system clock in order to make the +# synchronisation more reliable, uncomment (and edit) the following +# line. + +! minsources 2 + +# If your computer has a good stable clock (e.g. it is not a virtual +# machine), you might also want to reduce the maximum assumed drift +# (frequency error) of the clock (the value is specified in ppm). + +! maxdrift 100 + +# By default, chronyd allows synchronisation to an unauthenticated NTP +# source (i.e. specified without the nts and key options) if it agrees with +# a majority of authenticated NTP sources, or if no authenticated source is +# specified. If you don't want chronyd to ever synchronise to an +# unauthenticated NTP source, uncomment the first from the following lines. +# If you don't want to synchronise to an unauthenticated NTP source only +# when an authenticated source is specified, uncomment the second line. +# If you want chronyd to ignore authentication in the source selection, +# uncomment the third line. + +! authselectmode require +! authselectmode prefer +! authselectmode ignore + +####################################################################### +### FILENAMES ETC +# Chrony likes to keep information about your computer's clock in files. +# The 'driftfile' stores the computer's clock gain/loss rate in parts +# per million. When chronyd starts, the system clock can be tuned +# immediately so that it doesn't gain or lose any more time. You +# generally want this, so it is uncommented. + +driftfile /var/lib/chrony/drift + +# If you want to enable NTP authentication with symmetric keys, you will need +# to uncomment the following line and edit the file to set up the keys. + +! keyfile /etc/chrony.keys + +# If you specify an NTP server with the nts option to enable authentication +# with the Network Time Security (NTS) mechanism, or enable server NTS with +# the ntsservercert and ntsserverkey directives below, the following line will +# allow the client/server to save the NTS keys and cookies in order to reduce +# the number of key establishments (NTS-KE sessions). + +ntsdumpdir /var/lib/chrony + +# If chronyd is configured to act as an NTP server and you want to enable NTS +# for its clients, you will need a TLS certificate and private key. Uncomment +# and edit the following lines to specify the locations of the certificate and +# key. + +! ntsservercert /etc/.../nts-server.crt +! ntsserverkey /etc/.../nts-server.key + +# chronyd can save the measurement history for the servers to files when +# it exits. This is useful in 2 situations: +# +# 1. If you stop chronyd and restart it with the '-r' option (e.g. after +# an upgrade), the old measurements will still be relevant when chronyd +# is restarted. This will reduce the time needed to get accurate +# gain/loss measurements. +# +# 2. On Linux, if you use the RTC support and start chronyd with +# '-r -s' on bootup, measurements from the last boot will still be +# useful (the real time clock is used to 'flywheel' chronyd between +# boots). +# +# Uncomment the following line to use this. + +! dumpdir /var/lib/chrony + +# chronyd writes its process ID to a file. If you try to start a second +# copy of chronyd, it will detect that the process named in the file is +# still running and bail out. If you want to change the path to the PID +# file, uncomment this line and edit it. The default path is shown. + +! pidfile /var/run/chrony/chronyd.pid + +# The system timezone database usually comes with a list of leap seconds and +# corresponding TAI-UTC offsets. chronyd can use it to set the offset of the +# system TAI clock and have an additional source of leap seconds. + +! leapseclist /usr/share/zoneinfo/leap-seconds.list + +####################################################################### +### INITIAL CLOCK CORRECTION +# This option is useful to quickly correct the clock on start if it's +# off by a large amount. The value '1.0' means that if the error is less +# than 1 second, it will be gradually removed by speeding up or slowing +# down your computer's clock until it is correct. If the error is above +# 1 second, an immediate time jump will be applied to correct it. The +# value '3' means the step is allowed only in the first three updates of +# the clock. Some software can get upset if the system clock jumps +# (especially backwards), so be careful! + +! makestep 1.0 3 + +####################################################################### +### LEAP SECONDS +# A leap second is an occasional one-second correction of the UTC +# time scale. By default, chronyd tells the kernel to insert/delete +# the leap second, which makes a backward/forward step to correct the +# clock for it. As with the makestep directive, this jump can upset +# some applications. If you prefer chronyd to make a gradual +# correction, causing the clock to be off for a longer time, uncomment +# the following line. + +! leapsecmode slew + +####################################################################### +### LOGGING +# If you want to log information about the time measurements chronyd has +# gathered, you might want to enable the following lines. You probably +# only need this if you really enjoy looking at the logs, you want to +# produce some graphs of your system's timekeeping performance, or you +# need help in debugging a problem. + +! logdir /var/log/chrony +! log measurements statistics tracking + +# If you have real time clock support enabled (see below), you might want +# this line instead: + +! log measurements statistics tracking rtc + +####################################################################### +### ACTING AS AN NTP SERVER +# You might want the computer to be an NTP server for other computers. +# +# By default, chronyd does not allow any clients to access it. You need +# to explicitly enable access using 'allow' and 'deny' directives. +# +# e.g. to enable client access from the 192.168.*.* class B subnet, + +! allow 192.168/16 + +# .. but disallow the 192.168.100.* subnet of that, + +! deny 192.168.100/24 + +# You can have as many allow and deny directives as you need. The order +# is unimportant. + +# If you want to present your computer's time for others to synchronise +# with, even if you don't seem to be synchronised to any NTP servers +# yourself, enable the following line. The value 10 may be varied +# between 1 and 15. You should avoid small values because you will look +# like a real NTP server. The value 10 means that you appear to be 10 +# NTP 'hops' away from an authoritative source (atomic clock, GPS +# receiver, radio clock etc). + +! local stratum 10 + +# Normally, chronyd will keep track of how many times each client +# machine accesses it. The information can be accessed by the 'clients' +# command of chronyc. You can disable this facility by uncommenting the +# following line. This will save a bit of memory if you have many +# clients and it will also disable support for the interleaved mode. + +! noclientlog + +# The clientlog size is limited to 512KB by default. If you have many +# clients, you might want to increase the limit. + +! clientloglimit 4194304 + +# By default, chronyd tries to respond to all valid NTP requests from +# allowed addresses. If you want to limit the response rate for NTP +# clients that are sending requests too frequently, uncomment and edit +# the following line. + +! ratelimit interval 3 burst 8 + +####################################################################### +### REPORTING BIG CLOCK CHANGES +# Perhaps you want to know if chronyd suddenly detects any large error +# in your computer's clock. This might indicate a fault or a problem +# with the server(s) you are using, for example. +# +# The next option causes a message to be written to syslog when chronyd +# has to correct an error above 0.5 seconds (you can use any amount you +# like). + +! logchange 0.5 + +# The next option will send email to the named person when chronyd has +# to correct an error above 0.5 seconds. (If you need to send mail to +# several people, you need to set up a mailing list or sendmail alias +# for them and use the address of that.) + +! mailonchange wibble@example.net 0.5 + +####################################################################### +### COMMAND ACCESS +# The program chronyc is used to show the current operation of chronyd +# and to change parts of its configuration whilst it is running. + +# By default chronyd binds to the loopback interface. Uncomment the +# following lines to allow receiving command packets from remote hosts. + +! bindcmdaddress 0.0.0.0 +! bindcmdaddress :: + +# Normally, chronyd will only allow connections from chronyc on the same +# machine as itself. This is for security. If you have a subnet +# 192.168.*.* and you want to be able to use chronyc from any machine on +# it, you could uncomment the following line. (Edit this to your own +# situation.) + +! cmdallow 192.168/16 + +# You can add as many 'cmdallow' and 'cmddeny' lines as you like. The +# syntax and meaning is the same as for 'allow' and 'deny', except that +# 'cmdallow' and 'cmddeny' control access to the chronyd's command port. + +# Rate limiting can be enabled also for command packets. (Note, +# commands from localhost are never limited.) + +! cmdratelimit interval -4 burst 16 + +####################################################################### +### HARDWARE TIMESTAMPING +# On Linux, if the network interface controller and its driver support +# hardware timestamping, it can significantly improve the accuracy of +# synchronisation. It can be enabled on specified interfaces only, or it +# can be enabled on all interfaces that support it. + +! hwtimestamp eth0 +! hwtimestamp * + +####################################################################### +### REAL TIME CLOCK +# chronyd can characterise the system's real-time clock. This is the +# clock that keeps running when the power is turned off, so that the +# machine knows the approximate time when it boots again. The error at +# a particular epoch and gain/loss rate can be written to a file and +# used later by chronyd when it is started with the '-s' option. +# +# You need to have 'enhanced RTC support' compiled into your Linux +# kernel. (Note, these options apply only to Linux.) + +! rtcfile /var/lib/chrony/rtc + +# Your RTC can be set to keep Universal Coordinated Time (UTC) or local +# time. (Local time means UTC +/- the effect of your timezone.) If you +# use UTC, chronyd will function correctly even if the computer is off +# at the epoch when you enter or leave summer time (aka daylight saving +# time). However, if you dual boot your system with Microsoft Windows, +# that will work better if your RTC maintains local time. You take your +# pick! + +! rtconutc + +# By default chronyd assumes that the enhanced RTC device is accessed as +# /dev/rtc. If it's accessed somewhere else on your system (e.g. you're +# using devfs), uncomment and edit the following line. + +! rtcdevice /dev/misc/rtc + +# Alternatively, if not using the -s option, this directive can be used +# to enable a mode in which the RTC is periodically set to the system +# time, with no tracking of its drift. + +! rtcsync + +####################################################################### +### REAL TIME SCHEDULER +# This directive tells chronyd to use the real-time FIFO scheduler with the +# specified priority (which must be between 0 and 100). This should result +# in reduced latency. You don't need it unless you really have a requirement +# for extreme clock stability. Works only on Linux. Note that the "-P" +# command-line switch will override this. + +! sched_priority 1 + +####################################################################### +### LOCKING CHRONYD INTO RAM +# This directive tells chronyd to use the mlockall() syscall to lock itself +# into RAM so that it will never be paged out. This should result in reduced +# latency. You don't need it unless you really have a requirement +# for extreme clock stability. Works only on Linux. Note that the "-m" +# command-line switch will also enable this feature. + +! lock_all |