NTP Server for Linux experiments

One, NTP server (ip:192.168.1.101)

1. Installation: Yum install-y NTP

2. Firewall allowed: iptables-a input-i $EXTIF-P udp-s 192.168.1.0/24--dport 123-j ACCEPT

3. Configuration: vim/etc/ntp.conf

   Restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap

   Server before # Remove

4. Start:/ETC/INIT.D/NTPD start

   Chkconfig ntpd on

5. Observation: Ntpq-p or Ntpstat

Second, NTP client

1. Installation: Yum install-y ntpdate

2. Manual sync First: Ntpdate 192.168.1.101 (wrong: ntpdate-d 192.168.1.101)

3. Configuration: vim/etc/ntp.conf

   Server 192.168.1.101

4. Start:/ETC/INIT.D/NTPD start

   Chkconfig ntpd on

5. Write Crontab-e

   Add a row to synchronize with the time synchronization server 6:10 daily
   

   * * * */usr/sbin/ntpdate ntp-server IP >>/usr/local/logs/crontab/ntpdate.log

Attention:

1. Self-built NTP time cannot be too much worse than external server time
   

2. Firewall to allow UDP port 123

3. Need to wait a few minutes to take effect

4. The time error between server and client cannot be greater than 1000s
   

NTP Server for Linux experiments