Linux LAN Sync Time

2. Select a machine that can sisu the network as a time server (can not be on or on the optional one, but only to ensure that the LAN time synchronization)
4. Configure this time server
   • install NTP
   • Configure
     • [plain]  view plain  copy  
       1. restrict 127.0.0.1 //give native all permission   
       2. restrict -6 ::1 //not quite clear, for IPV6?   
       3. restrict 192.168.1.0 mask 255.255.255.0 nomodify  notrap //to the local area network host synchronization time permission, but does not allow the modification time server time   
       4. server 0.rhel.pool.ntp.org //time Server, The same   
       5. SERVER 1.RHEL.POOL.NTP.ORG  
       6. Server 2.rhel.po ol.ntp.org  
     • rest with default configuration
6. Configuring the machine inside the LAN
   • Installing NTP
   • Configuring in/ect/ntp.conf
     • Comment out the original extranet time server and add the Intranet time server:
     • 1. Server 192.168.1.100//modify IP for your intranet time server
   • Set up scheduled tasks that are synchronized once per hour:
     • 1. vi/etc/cron.hourly/ntpdatehourly.sh
       2. Add the following content:
       3. #!/bin/sh
       4. Ntpdate 192.168.1.100
   • Stop NTPD Services: Service NTPD stop
   • Manual synchronization time, performed on each node: ntpdate 192.168.1.100

• To set up an interval at any time on the basis of synchronization method:
  • Vi/etc/crontab, as follows:
  • From the general requirements that you can see the timing task instructions written
  • We can add a new timed task with CRONTAB-E and enter it in the new file edit box that pops up:
    • 1. */15 * * * * ntpdate 192.168.1.100
  • Then save exit, you will be prompted to add a new task (the above task represents "no interval 15 minutes to the time server 192.168.1.100 synchronization Time")
  • You can use the command crontab-u root-l to view the root user's scheduled tasks
• Linux scheduled tasks are pretty useful things, detailed explanation see my other blog: Click here

• Obviously, regardless of the way you synchronize time periodically, the NTPD service on the remaining nodes of the time server must be stopped.
• If you feel that your configuration is all fine, but the time is still not synchronized, then please pay attention to your firewall settings, namely: Service iptables

Linux LAN Sync Time