1.1 CentOS Linux release 7.7.1908 (Core)
1.2 ntp-4.2.6
rpm -qa | grep ntp
执行结果:
fontpackages-filesystem-1.44-8.el7.noarch ntpdate-4.2.6p5-28.el7.centos.x86_64 python-ntplib-0.3.2-1.el7.noarch
yum install ntp ntpdate -y
rpm -qa | grep ntp
执行结果:
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
systemctl status ntpd
执行结果:
● 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)
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
vim /etc/ntp.conf
把如下四行代码注释掉
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
在下面再添加一行
server 127.127.1.0 iburst
systemctl restart ntpd
or
service ntpd restart
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
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
systemctl enable ntpd
firewall-cmd --permanent --add-port=123/udp firewall-cmd --reload
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
ping 192.168.111.131
执行结果:
正在 Ping 192.168.111.131 具有 32 字节的数据: 来自 192.168.111.131 的回复: 字节=32 时间<1ms TTL=64 来自 192.168.111.131 的回复: 字节=32 时间<1ms TTL=64 来自 192.168.111.131 的回复: 字节=32 时间<1ms TTL=64 来自 192.168.111.131 的回复: 字节=32 时间<1ms TTL=64
执行“时间和日期” -> Internet时间 -> 更改设置
勾选“与Internet时间服务器同步”,输入NTP服务器IP地址,单击“立即更新”
显示同步成功
如果本地PC日期与NTP服务器跨度过大,比如相差16年,同步失败。可以先手动或者bat脚本调整大概日期,缩减跨度。
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
ntpdate -u 192.168.111.131
systemctl start ntpd
or
service ntpd start
systemctl enable ntpd
[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
参考文档:https://blog.csdn.net/hellboy0621/article/details/81903091
原文:https://www.cnblogs.com/hester/p/12313753.html