一·NTP伺服器搭建

1)安裝NTP服務

[root@localhost ~]# yum -y install ntp
[root@localhost ~]# vim /etc/ntp.conf 

restrict 172.25.0.0 mask 255.255.255.0 nomodify notrap          //新增接受的地址範圍
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.rhel.pool.ntp.org iburst
 

#server 1.rhel.pool.ntp.org iburst
#server 2.rhel.pool.ntp.org iburst
#server 3.rhel.pool.ntp.org iburst
server s1a.time.edu.cn iburst                                   //中國郵電大學NTP伺服器

[root@localhost ~]# systemctl start ntpd
[root@localhost ~]# systemctl enable ntpd

2）防火牆開啟埠，NTP預設埠號UDP123

[root@localhost
 
 ~]# firewall-cmd --add-service=ntp --permanent         //永久生效放行ntp服務
[root@localhost ~]# firewall-cmd --reload                      //重讀防火牆

3）檢視同步

[[email protected] ~]# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 

*10.112.202.in-a 202.118.1.46     2 u    9   64    1   93.632    9.389   5.115

4）配置ntp客戶端

[root@localhost ~]# yum -y install ntpdate                     //安裝客戶端軟體
[root@localhost ~]# ntpdate s1a.time.edu.cn                        //指定伺服器域名
[root@localhost ~]# systemctl restart ntpdate                      //重啟服務