CentOS7搭建NTP服务器及客户端同步时间

1. 查看服务器是否安装ntp,系统默认安装ntpdate

rpm -qa | grep ntp

结果:

fontpackages-filesystem-1.44-8.el7.noarch
ntpdate-4.2.6p5-28.el7.centos.x86_64
python-ntplib-0.3.2-1.el7.noarch

2.安装ntp ntpdate,其中ntpdate默认安装,可以只安装ntp

yum install ntp ntpdate -y

3.查看是否已安装完成,与第2步对比

rpm -qa | grep ntp

结果:

fontpackages-filesystem-1.44-8.el7.noarch
ntpdate-4.2.6p5-28.el7.centos.x86_64
ntp-4.2.6p5-28.el7.centos.x86_64
python-ntplib-0.3.2-1.el7.noarch

4.查看ntp服务器状态,两条命令效果一样

systemctl status ntpd

结果:

● ntpd.service - Network Time Service
Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
Active: inactive (dead)

or

service ntpd status

执行结果:

Redirecting to /bin/systemctl status ntpd.service
● ntpd.service - Network Time Service
Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
Active: inactive (dead)

5.修系统/运维改配置文件

使该NTP服务器在不联网的情况下,使用本服务器的时间作为同步时间

#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst

在下面再添加网络时间服务器一行

server 127.127.1.0 iburst

6.重启ntp服务

systemctl restart ntpd

or

service ntpd restart

7.再次查看服务器状态

systemctl status ntpd

执行结果:

● ntpd.service - Network Time Service
Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2018-08-21 14:29:12 CST; 8s ago
Process: 6588 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 6589 (ntpd)
Tasks: 1
CGroup: /system.slice/ntpd.service
└─6589 /usr/sbin/ntpd -u ntp:ntp -g

Aug 21 14:29:12 web ntpd[6589]: Listen normally on 2 lo 127.0.0.1 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 3 eno1 192.168.0.163 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 4 virbr0 192.168.122.1 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 5 lo ::1 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 6 eno1 fe80::6e92:bfff:fe6f:daea UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listening on routing socket on fd #23 for interface updates
Aug 21 14:29:12 web ntpd[6589]: 0.0.0.0 c016 06 restart
Aug 21 14:29:12 web ntpd[6589]: 0.0.0.0 c012 02 freq_set kernel 0.000 PPM
Aug 21 14:29:12 web ntpd[6589]: 0.0.0.0 c011 01 freq_not_set
Aug 21 14:29:13 web ntpd[6589]: 0.0.0.0 c514 04 freq_mode

or

service ntpd status

执行结果:

Redirecting to /bin/systemctl status ntpd.service
● ntpd.service - Network Time Service
Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2018-08-21 14:29:12 CST; 56s ago
Process: 6588 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 6589 (ntpd)
Tasks: 1
CGroup: /system.slice/ntpd.service
└─6589 /usr/sbin/ntpd -u ntp:ntp -g

Aug 21 14:29:12 web ntpd[6589]: Listen normally on 2 lo 127.0.0.1 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 3 eno1 192.168.0.163 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 4 virbr0 192.168.122.1 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 5 lo ::1 UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listen normally on 6 eno1 fe80::6e92:bfff:fe6f:daea UDP 123
Aug 21 14:29:12 web ntpd[6589]: Listening on routing socket on fd #23 for interface updates
Aug 21 14:29:12 web ntpd[6589]: 0.0.0.0 c016 06 restart
Aug 21 14:29:12 web ntpd[6589]: 0.0.0.0 c012 02 freq_set kernel 0.000 PPM
Aug 21 14:29:12 web ntpd[6589]: 0.0.0.0 c011 01 freq_not_set
Aug 21 14:29:13 web ntpd[6589]: 0.0.0.0 c514 04 freq_mode

8.查看是否同步

ntpq -p

执行结果:

remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*LOCAL(0) .LOCL. 5 l 20 64 7 0.000 0.000 0.000

9.设置开机启动

systemctl enable ntpd

10.设置防火墙,打开udp123端口

firewall-cmd --permanent --add-port=123/udp
firewall-cmd --reload

11.查看防火墙已打开端linux

iptables -L -n | grep 123

执行结果:

ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:123 ctstate NEW,UNTRACKED

12.L服务器租用多少钱一年inux client 配置

前5步与服务器一致,修改配置文件将刚刚搭建好的NTP服务器作为客户端上游时间服务器

vim /etc/ntp.conf

内容修改如下:

#注释掉其他上游时间服务器
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst
#配置上游时间服务器为本地的ntpd Server服务器
server 192.168.111.131
#配置允许上游时间服务器主动修改本机的时间
restrict 192.168.0.163 nomodify notrap noquery

13.与本地ntpd服务器地址 Server同步一下

ntpdate -u 192.168.111.131

14.启动ntp服服务器配置

systemctl start ntpd

or

service ntpd start

15.设置开机启动

systemctl enable ntpd

1服务器怎么搭建6.查看状态

[root@db3 ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
*192.168.111.131 LOCAL(0) 11 u 21 64 377 0.068 -0.824 0.367