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AlienVault® USM Appliance™

Known Issue: NTP Server Settings Not Applied to /etc/default/ntpdate

Reported Version: 5.2.2
Fixed Version 5.4.3
Deployment: All deployments
AlienVault Ticket ID ENG-103272

Description

This topic provides a method to manually update the NTP server setting in /etc/default/ntpdate.

The /etc/default/ntpdate file is not updated when you update the NTP Server information in the AlienVault USM Appliance Setup menu.

USM Appliance includes two ntpdate commands: ntpdate and ntpdate-debian.

  • USM Appliance runs ntpdate-debian during system boot up, and it uses the NTP server configured in /etc/default/ntpdate.
  • USM Appliance launches ntpdate hourly (from cron) to adjust the server time. This uses the NTP server you specified in the AlienVault Setup menu.

If you have deployed USM Appliance in a network with no access to the default servers specified in the /etc/default/ntpdate file, the cron job running every hour uses the customer-defined NTP servers so that time will be adjusted correctly.

However, in the case where Internet access is allowed and immediately after a reboot, USM Appliance uses the default NTP servers specified in /etc/default/ntpdate instead.

This can cause the system time to be incorrect for a max of 59 minutes following the initial boot. Once the hourly cron job executes, USM Appliance will update the system time using the customer specified NTP server, correcting the time.

Workaround

The workaround for this issue is to manually edit the /etc/default/ntpdate file so that it also uses the NTP servers you have specified in the AlienVault Setup menu.

1. Edit /etc/default/ntpdate and notice that "NTPSERVERS" are set to the Debian defaults:

# List of NTP servers to use (Separate multiple servers with spaces.)

# Not used if NTPDATE_USE_NTP_CONF is yes.

NTPSERVERS="0.debian.pool.ntp.org 1.debian.pool.ntp.org 2.debian.pool.ntp.org 3.debian.pool.ntp.org"

2. Modify that line so that it contains the correct NTP servers that you wish to use:

# List of NTP servers to use (Separate multiple servers with spaces.)

# Not used if NTPDATE_USE_NTP_CONF is yes.

NTPSERVERS="1.ie.pool.ntp.org 2.europe.pool.ntp.org 3.europe.pool.ntp.org"

3. Save our changes.