# 安装ntp服务
sudo apt-get install ntp ntpdate
# 修改ntp服务配置文件?
sudo vi /etc/ntp.conf
# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
# driftfile记录时间差异
driftfile /var/lib/ntp/ntp.drift
# Leap seconds definition provided by tzdata
# leapfile /usr/share/zoneinfo/leap-seconds.list
# Enable this if you want statistics to be logged.
# 使用statsdir和filegen开启统计分析
statsdir /var/log/ntpstats/
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
# Specify one or more NTP servers.
# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
#pool 0.ubuntu.pool.ntp.org iburst
#pool 1.ubuntu.pool.ntp.org iburst
#pool 2.ubuntu.pool.ntp.org iburst
#pool 3.ubuntu.pool.ntp.org iburst
# Use Ubuntu's ntp server as a fallback.
#pool ntp.ubuntu.com
# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
# details. The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
# might also be helpful.
#
# Note that "restrict" applies to both servers and clients, so a configuration
# that might be intended to block requests from certain clients could also end
# up blocking replies from your own upstream servers.
# By default, exchange time with everybody, but don't allow configuration.
restrict -4 default kod notrap nomodify nopeer noquery limited
restrict -6 default kod notrap nomodify nopeer noquery limited
# restrict default nomodify notrap nopeer noquery
# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1
# Needed for adding pool entries
# restrict source notrap nomodify noquery
# 任意IP都可以同步时间，不可以修改
# notrap不提供trap这个远程事件登录 nomodify客户端不能使用ntpc与ntpq这两个程序来修改服务器的时间参数
restrict 0.0.0.0 mask 255.255.255.0 nomodify notrap
# Clients from this (example!) subnet have unlimited access, but only if
# cryptographically authenticated.
#restrict 192.168.123.0 mask 255.255.255.0 notrust
# 网络时间 prefer，表示优先使用的服务器
server cn.pool.ntp.org prefer
#当没有时间同步源的时候会以自身硬件时间为准
server 127.127.1.0 prefer
Fudge 127.127.1.0 stratum 10
# If you want to provide time to your local subnet, change the next line.
# (Again, the address is an example only.)
#broadcast 192.168.123.255
# If you want to listen to time broadcasts on your local subnet, de-comment the
# next lines. Please do this only if you trust everybody on the network!
#disable auth
#broadcastclient
# 启动ntp服务
sudo systemctl restart ntp
# 查看ntp服务启动状态
sudo systemctl status ntp
# 检查本地ntp服务是否正常
ntpq -p
#查看是否开机启动
systemctl is-enabled ntp
#关闭开机启动
systemctl disable ntp
# 开启开机启动
sudo systemctl enable ntp.service