xref: /freebsd-11-stable/etc/ntp.conf

#
# $FreeBSD: stable/11/etc/ntp.conf 352865 2019-09-29 03:36:50Z cy $
#
# Default NTP servers for the FreeBSD operating system.
#
# Don't forget to enable ntpd in /etc/rc.conf with:
# ntpd_enable="YES"
#
# The driftfile is by default /var/db/ntpd.drift, check
# /etc/defaults/rc.conf on how to change the location.
#

#
# Set the target and limit for adding servers configured via pool statements
# or discovered dynamically via mechanisms such as broadcast and manycast.
# Ntpd automatically adds maxclock-1 servers from configured pools, and may
# add as many as maxclock*2 if necessary to ensure that at least minclock 
# servers are providing good consistant time.
#
tos minclock 3 maxclock 6

#
# The following pool statement will give you a random set of NTP servers
# geographically close to you.  A single pool statement adds multiple
# servers from the pool, according to the tos minclock/maxclock targets.
# See http://www.pool.ntp.org/ for details.  Note, pool.ntp.org encourages
# users with a static IP and good upstream NTP servers to add a server
# to the pool. See http://www.pool.ntp.org/join.html if you are interested.
#
# The option `iburst' is used for faster initial synchronization.
#
pool 0.freebsd.pool.ntp.org iburst

#
# If you want to pick yourself which country's public NTP server
# you want to sync against, comment out the above pool, uncomment
# the next one, and replace CC with the country's abbreviation.
# Make sure that the hostname resolves to a proper IP address!
#
# pool 0.CC.pool.ntp.org iburst

#
# To configure a specific server, such as an organization-wide local
# server, add lines similar to the following.  One or more specific
# servers can be configured in addition to, or instead of, any server
# pools specified above.  When both are configured, ntpd first adds all
# the specific servers, then adds servers from the pool until the tos
# minclock/maxclock targets are met.
#
#server time.my-internal.org iburst

#
# Security:
#
# By default, only allow time queries and block all other requests
# from unauthenticated clients.
#
# The "restrict source" line allows peers to be mobilized when added by
# ntpd from a pool, but does not enable mobilizing a new peer association
# by other dynamic means (broadcast, manycast, ntpq commands, etc).
#
# See http://support.ntp.org/bin/view/Support/AccessRestrictions
# for more information.
#
restrict default limited kod nomodify notrap noquery nopeer
restrict source  limited kod nomodify notrap noquery

#
# Alternatively, the following rules would block all unauthorized access.
#
#restrict default ignore
#
# In this case, all remote NTP time servers also need to be explicitly
# allowed or they would not be able to exchange time information with
# this server.
#
# Please note that this example doesn't work for the servers in
# the pool.ntp.org domain since they return multiple A records.
#
#restrict 0.pool.ntp.org nomodify nopeer noquery notrap
#restrict 1.pool.ntp.org nomodify nopeer noquery notrap
#restrict 2.pool.ntp.org nomodify nopeer noquery notrap
#
# The following settings allow unrestricted access from the localhost
restrict 127.0.0.1
restrict ::1

#
# If a server loses sync with all upstream servers, NTP clients
# no longer follow that server. The local clock can be configured
# to provide a time source when this happens, but it should usually
# be configured on just one server on a network. For more details see
# http://support.ntp.org/bin/view/Support/UndisciplinedLocalClock
# The use of Orphan Mode may be preferable.
#
#server 127.127.1.0
#fudge 127.127.1.0 stratum 10

# See http://support.ntp.org/bin/view/Support/ConfiguringNTP#Section_6.14.
# for documentation regarding leapfile. Updates to the file can be obtained
# from ftp://time.nist.gov/pub/ or ftp://tycho.usno.navy.mil/pub/ntp/.
# Use either leapfile in /etc/ntp or periodically updated leapfile in /var/db.
#leapfile "/etc/ntp/leap-seconds"
leapfile "/var/db/ntpd.leap-seconds.list"

# Specify the number of megabytes of memory that should be allocated and
# locked. -1 (default) means "do not lock the process into memory".
# 0 means "lock whatever memory the process wants into memory". Any other
# number means to lock up to that number of megabytes into memory.
# 0 may result in a segfault when ASLR with stack gap randomization
# is enabled.
#rlimit memlock 32