Table of Contents
Advertisement
Chapter 6: Defining Background Scans
Determining When Background Scans Run
Introduction
Scanning refresh
cycles
Important points
about refresh
cycles
Scanning windows
Scans affected by
scanning windows
Cycle and window
dependencies
Example
82
This topic describes two important concepts for background scanning—scanning refresh
cycles and scanning windows. These concepts control when background scans run.
A scanning refresh cycle is the maximum duration (in days, weeks, or months) of a
background scan. You define scanning refresh cycles separately for discovery and for
assessment scans in a Scan Control policy, and the cycles apply to the scans for all groups
that the policy controls.
Refresh cycles affect scanning as follows:
Refresh cycles apply to background discovery and background assessment scans;
●
they do not apply to ad hoc scans.
At the end of a refresh cycle, any background scanning jobs that are still running are
●
stopped and do not run to completion. Their status appears as Expired.
The refresh cycle begins at midnight on the first day of the cycle, and the jobs for that
●
cycle are scheduled in the Command Jobs window at that time.
Scanning windows are the hours that are available for scanning each day of the week. A
scan that runs only during scanning windows pauses when a window closes and resumes
when the window reopens.
Scanning windows affect scans as follows:
Scanning windows apply to all background scans for the groups controlled by a
●
particular Scan Windows policy.
When you run an ad hoc scan, you choose whether to confine the scan to the user-
●
defined scanning windows.
Background scanning for a group requires a refresh cycle and one or more scanning
windows. Although you define refresh cycles and scanning windows in different policies,
they work together to define the extent of your background scans. The cycle defines the
duration, or elapsed time, of the scan; the scanning windows define the days and hours
when scanning may occur during the cycle.
Figure 21 illustrates a two-week scanning refresh cycle that has different scan windows
for weekdays and for each day of the weekend. In this example, scans can run from 10:00
IBM Internet Security Systems
Advertisement
Table of Contents
