Install and use Chrony, and then build your own time server

Preface

Here we use chrony To build a time server , Here we need to do some operations on the firewall , Let's just shut it down .

chrony brief introduction
chrony It's a ntp Protocol implementation program , It can be used as a server , It can also act as a client , It can keep the system clock synchronized with the clock server , Keep time accurate .

Anyway, he's better than NTP There are great advantages , We don't talk much , Go straight to work

install

yum install chrony -y

View existing files

rpm -ql chrony

Let's change the time to the wrong time , Used for testing
Start the service

systemctl start chronyd
chronyc sources

We can also write multiple time servers , Convenient for system query （ Time server address ）

vim /etc/chrony.conf

* Represents the upper layer currently in use NTP
+ Successful connection , An alternate server that can provide time updates
- The NTP The server is considered unqualified

（ If you play a bunch of question marks , It is suggested to try more ）

Time server

We installed it on both operating systems chrony, Now try to get one of them to get time from the other
At this time, the host as the server should deal with the firewall and selinux Make some settings , For the convenience of the experiment , Let's just close

systemctl stop firewalld

close selinux Some files need to be modified

vim /etc/selinux/config

Close it now

setenforce 0

Let's make sure the server and client , And change the host name （hostname Host name ）


At this time , Check the server's IP, test Ping（ping 192.168.32.128）

Sure Ping through , Will server's IP Write to the client chrony The configuration file （vim /etc/chrony.conf）

Restart the service ！！！
After editing the configuration file, don't forget to restart the service

systemctl restart chronyd

Write the allowed access in the configuration file of the server （vim /etc/chrony.conf, All... Are allowed here ）

Remember to restart the service

Modify the time of the client to the wrong time （date -s 10:00）

Use the time server to get the time （chronyc sources）
Remember to restart the service