Learn Bird Brother Linux service-ntp time server

Test machine: CentOS 6.5

ipaddr=192.168.1.229

Rqm-qa |grep NTP

Not installed, first installed

Yum-y Intall NTP

Configuration file Location

Vim/etc/ntp.conf

Driftfile/var/lib/ntp/drift #这个代表上层服务与本机主板时钟之间时间差别记录在这个文件里

Restrict #管理权限

Restrict default kod nomodify notrap nopeer noquery #拒绝IPV4用户

restrict-6 default kod nomodify notrap nopeer noquery #拒绝IPV6用户

The parameters are as follows:

Ignore: Turn off all NTP Online Services

Nomodify: The client cannot change the time parameters on the server side, but the client can perform the network calibration via the server.

Notrust: The client source will be treated as untrusted subnet unless authenticated

Noquery: No time query for clients: Client cannot query NTP server using commands such as Ntpq,ntpc

Notrap: Do not provide trap remote login: Deny the matching host to provide mode 6 control message Trap Service. The Trap service is a subsystem of the NTPDQ Control Message Protocol, which is used for remote event logger applications.

Nopeer: Used to prevent the host from attempting to peer to the server and allow the fraudulent server to control the clock

Kod: The Kod package is sent when an access violation occurs.

RESTRICT-6 represents the permission settings for the IPV6 address.

So we're going to add a rule to release the local network segment.

Restrict 192.168.1.0 mask 255.255.255.0 nomdify notrap

Change the time that the upper-level time server is used to update the machine.

Comment out the CentOS time server to increase the server in China

#server 0.centos.pool.ntp.org Iburst

#server 1.centos.pool.ntp.org Iburst

#server 2.centos.pool.ntp.org Iburst

#server 3.centos.pool.ntp.org Iburst

Server 1.cn.pool.ntp.org prefer #prefer Express priority

Server 127.127.1.0 #127.127.1.0 represents the native hardware clock, which is used when the network is not available!

Save exit

/ETC/INIT.D/NTPD restart

Ntpstat View server sync with upper layer

[Email protected] ~]# Ntpstat

Synchronised to NTP server (110.75.186.248) at Stratum 3

Time correct to within 1974 MS

Polling server every S

Sync successfully

View status

Ntpq-p

[Email protected] ~]# ntpq-p

Remote refID St T when poll reach delay offset jitter

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

*ntp2.aliyun.com 10.137.38.86 2 u 11 64 77 35.382 0.544 0.520

LOCAL (0).           Locl. 5 l-64 0 0.000 0.000 0.000

Remote-the IP or hostname of the native and upper NTP, "+" is preferred, "*" indicates a secondary priority

refID-refer to the previous level of NTP host address

St-stratum stratum

When-how many seconds ago the time has been synchronized

Poll-How many seconds after the next update

Reach-Number of times an update has been requested to the upper NTP server

Delay-Network latency

Offset-time compensation

Jitter-system time vs. BIOS difference

Watch "Ntpq-p" Check the status of this command process.

Then use Windows to request time synchronization to the 192.168.1.229 server successfully.

Configuration complete

Learn Bird Brother Linux service-ntp time server