一、服务器配置
1、查看服务器、客户端操作系统版本
[root@hadoop101 ~]# cat /etc/redhat-release CentOS Linux release 7.6.1810 (Core)
2、查看服务器是否安装ntp，系统默认安装ntpdate；
[root@hadoop101 ~]# rpm -qa | grep ntp fontpackages-filesystem-1.44-8.el7.noarch ntpdate-4.2.6p5-28.el7.centos.x86_64 python-ntplib-0.3.2-1.el7.noarch ntp-4.2.6p5-28.el7.centos.x86_64
3、安装ntp ntpdate，其中ntpdate默认安装，可以只安装ntp；
yum install ntp ntpdate -y
4、查看ntp服务器状态，两条命令效果一样
[root@hadoop101 ~]# systemctl status ntpd ● ntpd.service - Network Time Service Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled) Active: inactive (dead)
或
[root@hadoop101 ~]# service ntpd status 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)
6、修改配置文件，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
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
在下面再添加两行
server 127.127.1.0 fudge 127.127.1.0 stratum 0
配置后：
[root@hadoop101 ~]# vim /etc/ntp.conf # For more information about this file, see the man pages # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5). driftfile /var/lib/ntp/drift # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. restrict default nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. restrict 127.0.0.1 restrict ::1 # Hosts on local network are less restricted. #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #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 server 127.127.1.0 fudge 127.127.1.0 stratum 0 #broadcast 192.168.1.255 autokey # broadcast server #broadcastclient # broadcast client #broadcast 224.0.1.1 autokey # multicast server #multicastclient 224.0.1.1 # multicast client #manycastserver 239.255.254.254 # manycast server #manycastclient 239.255.254.254 autokey # manycast client # Enable public key cryptography. #crypto includefile /etc/ntp/crypto/pw # Key file containing the keys and key identifiers used when operating # with symmetric key cryptography. keys /etc/ntp/keys # Specify the key identifiers which are trusted. #trustedkey 4 8 42 # Specify the key identifier to use with the ntpdc utility. #requestkey 8 # Specify the key identifier to use with the ntpq utility. #controlkey 8 # Enable writing of statistics records.
7、启动ntp服务
systemctl start ntpd
或
service ntpd start
8、再次查看服务器状态是否配置成功
[root@hadoop101 ~]# systemctl status ntpd
或
[root@hadoop101 ~]# service ntpd status
9、查看是否同步
[root@hadoop101 ~]# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== *LOCAL(0) .LOCL. 5 l 20 64 7 0.000 0.000 0.000
10、设置开机启动
[root@hadoop101 ~]# systemctl enable ntpd Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.
11、设置防火墙，打开udp123端口
[root@hadoop101 ~]# firewall-cmd --permanent --add-port=123/udp success [root@hadoop101 ~]# firewall-cmd --reload success
12、查看防火墙已打开端口
iptables -L -n
二、客户端配置
前5步与服务器一致
6、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 #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 hadoop101.com fudge hadoop101.com stratum 0 #配置允许上游时间服务器主动修改本机的时间 restrict hadoop101.com nomodify notrap noquery
配置后：
[root@hadoop103 ~]# vi /etc/ntp.conf # For more information about this file, see the man pages # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5). driftfile /var/lib/ntp/drift # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. #restrict default nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. #restrict 127.0.0.1 #restrict ::1 # Hosts on local network are less restricted. #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap restrict hadoop101.com nomodify notrap noquery # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #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 server hadoop101.com fudge hadoop101.com stratum 0 #broadcast 192.168.1.255 autokey # broadcast server #broadcastclient # broadcast client #broadcast 224.0.1.1 autokey # multicast server #multicastclient 224.0.1.1 # multicast client #manycastserver 239.255.254.254 # manycast server #manycastclient 239.255.254.254 autokey # manycast client # Enable public key cryptography. #crypto includefile /etc/ntp/crypto/pw # Key file containing the keys and key identifiers used when operating # with symmetric key cryptography. keys /etc/ntp/keys # Specify the key identifiers which are trusted. #trustedkey 4 8 42 # Specify the key identifier to use with the ntpdc utility. #requestkey 8 # Specify the key identifier to use with the ntpq utility.
7、与本地ntpd Server同步一下
[root@hadoop102 ~]# ntpdate -u hadoop101.com 15 Aug 11:33:35 ntpdate[8768]: adjust time server 192.168.1.101 offset 0.004621 sec
8、启动ntp服务
systemctl start ntpd
或
service ntpd start
9、设置开机启动
[root@hadoop102 ~]# systemctl enable ntpd Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.
10、查看状态
[root@hadoop103 ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
hadoop101.com .LOCL. 1 u 13 64 1 8.148 -2.581 0.000
参考：https://blog.csdn.net/hellboy0621/article/details/81903091