Create Configuration Files

About this task

Perform the following steps as user root on the machine:

Procedure

  1. Create file /etc/ntp/step-tickers. You can back up any existing version of the file. The file contains the host names or IP addresses of the NTP servers to contact during startup to initially set the time. If you use the NTP server pool, you must use host names, which requires DNS.
    For example, if the two NTP servers to use are 1.2.3.4 and 5.6.7.8, then use the following commands to create the file: 
    
echo 1.2.3.4 > /etc/ntp/step-tickers
echo 5.6.7.8 >> /etc/ntp/step-tickers
  2. Create file /etc/ntp.conf with the following commands. You can back up any existing version of the file. 
    
echo restrict default ignore > /etc/ntp.conf
echo restrict 127.0.0.1 >> /etc/ntp.conf
echo driftfile /var/lib/ntp/drift >> /etc/ntp.conf
  3. Add entries by using the restrict and server keywords for each NTP server. The following example adds entries for the hypothetical 1.2.3.4 and 5.6.7.8 NTP servers. The mask, nomodify, notrap, and noquery options prevent the server from modifying the NTP service on the Network Capture host machine. 
    
nullecho
restrict 1.2.3.4 mask 255.255.255.255 nomodify notrap noquery >> /etc/ntp.con
echo server 1.2.3.4 >> /etc/ntp.conf
echo restrict 5.6.7.8 mask 255.255.255.255 nomodify notrap noquery >> \
/etc/ntp.con
echo server 5.6.7.8 >> /etc/ntp.conf