Deploy NTP servers for time synchronization

A. Environment Preparation

xuegod63.cn Service Side

xuegod64.cn Client

two. Server-side configuration:

1. Installing the NTP service

[[email protected] ~]# Yum install-y NTP

2. turn on the NTPD service and set the boot up

[[Email protected] ~]# service NTPD start

Starting ntpd: [OK]

[Email protected] ~]# chkconfig ntpd on

3. To see if the port is started

[Email protected] ~]# netstat-anput| grep 123

UDP 0 0 172.16.30.39:123 0.0.0.0:* 2107/ntpd

udp        0      0 127.0.0.1:123                0.0.0.0:*                                 2107/ntpd          

udp        0      0 0.0.0.0:123                  0.0.0.0:*                                 2107/ntpd           

udp        0      0fe80::5054:ff:fee4:1f53:123:::*                                      2107/ntpd           

udp        0      0::1:123                      :::*                                      2107/ntpd           

UDP 0 0::: 123:::* 2107/ntpd

4. Sync Time:

[email protected] ~]# ntpdate0.centos.pool.ntp.org (because the NTPD service sync time error is turned on)

11:30:47 ntpdate[2116]: The NTP socketis in use, exiting

[[Email protected] ~]# service NTPD stop

Close ntpd: [OK]

[Email protected] ~]# ntpdate0.centos.pool.ntp.org

May 11:31:40 ntpdate[2128]: adjust Timeserver 202.112.29.82 offset-0.018094 sec

5. To Modify a configuration file:

[Email protected] ~]# vim/etc/ntp.conf

Restrict 127.0.0.1

Restrict-6:: 1

Restrict 192.168.1.0 mask 255.255.255.0 # allow access to 192.168.1.0 network segments

Server 127.127.1.0 # Local Clock address

Fudge 127.127.1.0 Stratum Local 127.127.1.0 is 10th floor

6. Restart ntpd Service

[Email protected] ~]#/etc/init.d/ntpd restart

Close ntpd: [Failed]

Starting ntpd: [OK]

7. Test:

Before testing, to detect whether the firewall, SELinux are off!!!

Service side:

[[Email protected] ~]# Date

. May 24 Tuesday 15:54:55 CST

[email protected] ~]# date-s "2016-05-2415:30" # Set the time

. May 24 Tuesday 15:30:00 CST

[email protected] ~]# Clock–w # Synchronize to hardware simultaneously

[[Email protected] ~]# Date

. May 24 Tuesday 15:30:14 CST

[Email protected] ~]# service ntpd restart

Close ntpd: [OK]

Starting ntpd: [OK]

[[Email protected] ~]# Date

. May 24 Tuesday 15:30:29 CST

Three Client testing:

[Email protected] ~]# ntpdate 172.16.30.39

May 15:30:37 ntpdate[15939]: Step timeserver 172.16.30.39 offset-1504.826538 sec

[[Email protected] ~]# Date

Tue 15:30:40 CST 2016

Common errors:

APR 15:30:17 ntpdate[11520]: noserver suitable for synchronization found

In fact, this is not a mistake. Instead, it takes approximately 3-5 minutes after each restart of the NTP server for the client to establish a normal communication connection with the server. This information is reported when the client connects to the server at this time. It usually takes a few minutes to wait.

This article is from the "Mo Hua Kai" blog, please be sure to keep this source http://ruofeng.blog.51cto.com/4313888/1782610

Deploy NTP servers for time synchronization