Build a Linux time server

Boring tonight, learning to build a Linux time server, in fact, quite simple, this article is mainly a summary of my, we can learn from it.

Required Packages:NTP

Configure Server-side

1, first check whether the NTP package is installed, check the command Rpm-qa | grep ntp or yum list | grep NTP

2, confirm the installation of the NTP package, to set up a local time server, only need to modify the/etc/ntp.conf file in a few simple configuration can be, vi/etc/ntp.conf

Just add on who can send a request to this server to update the time.

Restrict 192.168.100.0 mask 255.255.255.0 nomodify (allow intranet communication)

Restrict 0.0.0.0 mask 0.0.0.0 nomodify notrap noquery notrust (block other IP over update time)

　　

Description: About the Permission settings section

The setting of the permission is mainly set by the Restrict parameter, the main syntax is:

restrict IP address or domain name mask subnet mask option

Where IP can be an IP address or default, default means all IP.

Common options are as follows:

　　Ignore: Indicates that the NTP request packet is forbidden to enter

　　nomodify: Indicates that other computers are prevented from changing the native NTP service settings, but can be used through this NTP server for network

　　notrust: Disallowed, so unauthenticated NTP packets are not entered

Noquery: Indicates that other computers are prevented from querying the state of the native NTP service

If no option is set, it means that the computer (or network) has no restrictions

As for the server time update, the configuration file has been written,

Server 0.pool.ntp.org
Server 1.pool.ntp.org
Server 2.pool.ntp.org

Here there is no need to modify, as to the specific situation, today is too tired, to write a specific tomorrow.

Configuration of the Client

The client wants to synchronize time, only need to use a command to be able to ntpdate IP .

Concrete things, add again tomorrow.

This article is from the "focus on Java,linux Technology" blog, please be sure to keep this source http://wuqinglong.blog.51cto.com/9087037/1618328

Build a Linux time server