基于CentOS 7

规划

比如有2台机器

IP

主机名

说明

192.168.103.51

cdh51

本地NTP服务端

192.168.103.52

cdh52

本地NTP客户端

安装NTP服务

每台机器都安装ntp

yum -y install ntp

NTP服务端（cdh51）配置

/etc/ntp.conf配置

copy
driftfile /var/lib/ntp/drift

restrict default nomodify notrap nopeer noquery

restrict 127.0.0.1 
restrict ::1

# 添加该行允许某个网段服务器从该服务同步时间
restrict 192.168.103.0 mask 255.255.255.0 nomodify notrap

# 本地NTP服务同外网NTP服务同步时间
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

includefile /etc/ntp/crypto/pw

keys /etc/ntp/keys

disable monitor

执行 ntpdate 0.centos.pool.ntp.org ，手动做一次时间同步。再执行systemctl start ntpd

查看同步情况：

copy
# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+ntp1.ams1.nl.le 130.133.1.10     2 u  253  256  377  229.358   -2.606  10.955
+ntp.wdc1.us.lea 130.133.1.10     2 u  459  128  150  331.680  -44.356  17.944
*85.199.214.100  .GPS.            1 u  384   64  140  215.429   10.354  22.668

NTP服务端（cdh51）配置

/etc/ntp.conf配置

copy
driftfile /var/lib/ntp/drift

restrict default nomodify notrap nopeer noquery

restrict 127.0.0.1 
restrict ::1

# 同NTP服务端cdh51同步时间
server cdh51 iburst

includefile /etc/ntp/crypto/pw

keys /etc/ntp/keys

disable monitor

执行 ntpdate cdh51 ，手动做一次时间同步。再执行systemctl start ntpd

查看同步情况：

copy
# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*cdh51           85.199.214.100   2 u   52  128  377    0.322   -3.060   0.674