RHEL7下ntp

开始之前先把firewalld和selinux关闭

[root@localhost ~]# systemctl stop firewalld.service
[root@localhost ~]# setenforce 0   #临时关闭selinux 立即生效
[root@localhost ~]# vim /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled   #永久关闭 重启生效
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

配置源的部分就不说了

安装

 [root@localhost ftp]# yum install ntp -y
已加载插件：langpacks, product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
正在解决依赖关系
--> 正在检查事务
---> 软件包 ntp.x86_64.0.4.2.6p5-18.el7 将被 安装
--> 解决依赖关系完成

依赖关系解决

--------------省略部分--------------
已安装:
  ntp.x86_64 0:4.2.6p5-18.el7                                                                                          

完毕！

配置

在配置文件/etc/ntp.conf中修改

restrict 10.0.0.0 mask 255.0.0.0 nomodify notra
授权10.0.0.0网段上的所有机器可以从这台机器上查询和同步时间.
#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
如果ntp服务器无法联网，可以把从外网同步时间注释掉。

server  127.127.1.0     # local clock  
fudge   127.127.1.0 stratum 10
当外部时间不可用时，使用本地时间.

启动

[root@localhost ~]# systemctl start ntpd.service

测试

 [root@localhost ~]# date 
2019年 03月 14日 星期四 01:11:01 CST
[root@localhost ~]#