【CentOS】NTP Server

23112312

///
/// 安装
///

[iyunv@wode012 mysql]# yum install ntp

已加载插件：fastestmirror, langpacks

Repository base is listed more than once in the configuration

Repository updates is listed more than once in the configuration

Repository extras is listed more than once in the configuration

Repository centosplus is listed more than once in the configuration

Repository contrib is listed more than once in the configuration

Loading mirror speeds from cached hostfile

* base: mirrors.aliyun.com

* extras: mirrors.aliyun.com

* updates: mirrors.aliyun.com

软件包 ntp-4.2.6p5-19.el7.centos.3.x86_64 已安装并且是最新版本

无须任何处理

[iyunv@wode012 mysql]#

///

/// vi /etc/ntp.conf
///

restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap

server time.lib.tsinghua.edu.cn

server cn.pool.ntp.org

///

/// systemctl enable/status/start

///

[iyunv@wode012 etc]# systemctl enable ntpd.service

[iyunv@wode012 etc]# systemctl status ntpd.service

ntpd.service - Network Time Service

   Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled)

   Active: inactive (dead)

[iyunv@wode012 etc]# systemctl start ntpd.service

[iyunv@wode012 etc]# systemctl status ntpd.service

ntpd.service - Network Time Service

   Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled)

   Active: active (running) since 六 2015-11-14 23:48:34 CST; 2s ago

  Process: 26192 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 26193 (ntpd)

   CGroup: /system.slice/ntpd.service

           └─26193 /usr/sbin/ntpd -u ntp:ntp -g

///

/// firewall

///

[iyunv@wode012 services]# firewall-cmd --add-service=ntp --permanent

success

[iyunv@wode012 services]# firewall-cmd --list-all

public (default, active)

  interfaces: enp3s0f0 enp3s0f1

  sources:

  services: dhcpv6-client mysql ssh

  ports: 8703/tcp

  masquerade: no

  forward-ports:

  icmp-blocks:

  rich rules:

       

[iyunv@wode012 services]# firewall-cmd --reload

success

[iyunv@wode012 services]# firewall-cmd --list-all

public (default, active)

  interfaces: enp3s0f0 enp3s0f1

  sources:

  services: dhcpv6-client mysql ntp ssh

  ports:

  masquerade: no

  forward-ports:

  icmp-blocks:

  rich rules:

       

[iyunv@wode012 services]#

// for old version, iptables

iptables -A INPUT -p udp -dport 123 -j ACCEPT

///

/// check on server

///

[iyunv@wode012 etc]# ntpq -p

     remote           refid      st t when poll reach   delay   offset  jitter

==============================================================================

web.lib.tsinghu .INIT.          16 u    -   64    0    0.000    0.000   0.000

+news.neu.edu.cn 202.118.1.46     2 u   24   64    1   12.675   -5.860   0.000

+dns1.synet.edu. 202.118.1.46     2 u   14   64    1   12.546   -5.778   1.238

*202.118.1.130   202.118.1.46     2 u   13   64    1   12.399   -5.711   0.797

dns.sjtu.edu.cn .INIT.          16 u    -   64    0    0.000    0.000   0.000

///

/// test on client

///

#!/bin/bash

# sync time

/usr/sbin/ntpdate 192.168.1.134

# write to hw

/usr/sbin/hwclock -w