Information
System time should be synchronized between all systems in an environment. This is typically done by establishing an authoritative time server or set of servers and having all systems synchronize their clocks to them.
Note:
- On virtual systems where host based time synchronization is available consult your virtualization software documentation and verify that host based synchronization is in use and follows local site policy. In this scenario, this section should be skipped
- Only one time synchronization method should be in use on the system. Configuring multiple time synchronization methods could lead to unexpected or unreliable results
Time synchronization is important to support time sensitive security mechanisms and ensures log files have consistent time records across the enterprise, which aids in forensic investigations.
Solution
On physical systems, and virtual systems where host based time synchronization is not available.
Select one of the three time synchronization daemons; chrony (1) systemd-timesyncd (2) or ntp (3) and following the remediation procedure for the selected daemon.
Note: enabling more than one synchronization daemon could lead to unexpected or unreliable results:
- chrony
Run the following command to install chrony :
# apt install chrony
Run the following commands to stop and mask the systemd-timesyncd daemon:
# systemctl stop systemd-timesyncd.service
# systemctl --now mask systemd-timesyncd.service
Run the following command to remove the ntp package:
# apt purge ntp
NOTE:
- Subsection:
Configure chrony
should be followed
- Subsections:
Configure systemd-timesyncd
and
Configure ntp
should be skipped
<xhtml:ol start="2"> - systemd-timesyncd
Run the following command to remove the chrony package:
# apt purge chrony
Run the following command to remove the ntp package:
# apt purge ntp
NOTE:
- Subsection:
Configure systemd-timesyncd
should be followed
- Subsections:
Configure chrony
and
Configure ntp
should be skipped
<xhtml:ol start="3"> - ntp
Run the following command to install ntp :
# apt install ntp
Run the following commands to stop and mask the systemd-timesyncd daemon:
# systemctl stop systemd-timesyncd.service
# systemctl --now mask systemd-timesyncd.service
Run the following command to remove the chrony package:
# apt purge chrony
NOTE:
- Subsection:
Configure ntp
should be followed
- Subsections:
Configure chrony
and
Configure systemd-timesyncd
should be skipped