1 基本原理描述
1.1 原理
在离线的局域网内,存在不少于2台服务器。
选择一台服务器作为时间基准,配置为NTP Server;
其他服务器向时间基准服务器同步,配置为NTP Client。
1.2 描述
2 配置方法
2.1 NTP Server配置方法
1) 首先,确保操作系统防火墙关闭。
通过执行sudo systemctl status firewalld命令查看;
若未关闭,则执行
sudo systemctl stop firewalld
sudo systemctl disable firewalld
进行防火墙关闭。
2) 检查chronyd服务是否安装和激活
通过执行sudo systemctl status chronyd命令查看;
若未安装和激活,则执行以下命令
安装命令: sudo yum install chronyd
激活命令: sudo systemclt start chronyd
sudo systemctl enable chronyd
3) 更改配置文件,配置为server模式
编辑文件/etc/chrony.conf
内容如下:
# Use public servers from the pool.ntp.org project.# Please consider joining the pool (http://www.pool.ntp.org/join.html).#pool pool.ntp.org iburstserver ntp.ntsc.ac.cn iburstserver ntp1.aliyun.com iburst#server cn.pool.ntp.org iburst# Record the rate at which the system clock gains/losses time.driftfile /var/lib/chrony/drift# Allow the system clock to be stepped in the first three updates# if its offset is larger than 1 second.makestep 1.0 3# Enable kernel synchronization of the real-time clock (RTC).rtcsync# Enable hardware timestamping on all interfaces that support it.#hwtimestamp *# Increase the minimum number of selectable sources required to adjust# the system clock.#minsources 2# Allow NTP client access from local network.注意下面是允许的网段allow 192.168.0.0/16# Serve time even if not synchronized to a time source.允许离线校时local stratum 10# Specify file containing keys for NTP authentication.#keyfile /etc/chrony.keys# Get TAI-UTC offset and leap seconds from the system tz database.#leapsectz right/UTC# Specify directory for log files.logdir /var/log/chrony# Select which information is logged.#log measurements statistics tracking
4) 重新运行服务,自动加载更新的配置文件
sudo systemctl restart chronyd
5) 激活服务
运行命令: chronyc activity
应有类似如下返回
200 OK
0 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
2 sources with unknown address
6) 查看同步源
执行命令 chronyc sources
因为离线,返回如下
210 Number of sources = 0
MS Name/IP address Stratum Poll Reach LastRx Last sample
7) 查看同步情况
执行命令 chronyc tracking
返回如下:
Reference ID : 7F7F0101 ()
Stratum : 10
Ref time (UTC) : Sat Sep 13 03:05:36 2025
System time : 0.000000000 seconds fast of NTP time
Last offset : +0.000000000 seconds
RMS offset : 0.000000000 seconds
Frequency : 0.000 ppm slow
Residual freq : +0.000 ppm
Skew : 0.000 ppm
Root delay : 0.000000000 seconds
Root dispersion : 0.000000000 seconds
Update interval : 0.0 seconds
Leap status : Normal
2.2 NTP Client配置方法
1) 首先,确保操作系统防火墙关闭。
通过执行sudo systemctl status firewalld命令查看;
若未关闭,则执行
sudo systemctl stop firewalld
sudo systemctl disable firewalld
进行防火墙关闭。
2) 检查chronyd服务是否安装和激活
通过执行sudo systemctl status chronyd命令查看;
若为安装和激活,则执行以下命令
安装命令 sudo yum install chronyd
激活命令 sudo systemclt start chronyd
sudo systemctl enable chronyd
3) 更改配置文件,配置为server模式
编辑文件/etc/chrony.conf
内容如下:
# Use public servers from the pool.ntp.org project.# Please consider joining the pool (http://www.pool.ntp.org/join.html).#pool pool.ntp.org iburst# 注意以下是server的ip地址server 192.168.1.86 iburstserver ntp.ntsc.ac.cn iburstserver ntp1.aliyun.com iburst#server cn.pool.ntp.org iburst# Record the rate at which the system clock gains/losses time.driftfile /var/lib/chrony/drift# Allow the system clock to be stepped in the first three updates# if its offset is larger than 1 second.makestep 1.0 3# Enable kernel synchronization of the real-time clock (RTC).rtcsync# Enable hardware timestamping on all interfaces that support it.#hwtimestamp *# Increase the minimum number of selectable sources required to adjust# the system clock.#minsources 2# Allow NTP client access from local network.#allow 192.168.0.0/16# Serve time even if not synchronized to a time source.#local stratum 10# Specify file containing keys for NTP authentication.#keyfile /etc/chrony.keys# Get TAI-UTC offset and leap seconds from the system tz database.#leapsectz right/UTC# Specify directory for log files.logdir /var/log/chrony# Select which information is logged.#log measurements statistics tracking
4) 重新运行服务,自动加载更新的配置文件
sudo systemctl restart chronyd
5) 激活服务
运行命令 chronyc activity
应有类似如下返回
200 OK
0 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
2 sources with unknown address
6) 查看同步源
执行命令 chronyc sources
返回如下,应该有server的ip地址
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* 192.168.1.86 10 6 17 6 +4489ns[ +14us] +/- 35us
7) 查看同步情况
执行命令 chronyc tracking
返回如下:
Reference ID : C0A80156 (192.168.1.86)
Stratum : 11
Ref time (UTC) : Sat Sep 13 03:10:51 2025
System time : 0.000000002 seconds slow of NTP time
Last offset : +0.000009667 seconds
RMS offset : 0.000009667 seconds
Frequency : 3.457 ppm fast
Residual freq : +0.000 ppm
Skew : 174.367 ppm
Root delay : 0.000068986 seconds
Root dispersion : 0.006962806 seconds
Update interval : 2.0 seconds
Leap status : Normal