FortiSIEM Setting Rules for Event Dropping

Setting Rules for Event Dropping

Some devices and applications generate a significant number of logs, which may be very verbose, contain little valuable information, and consume storage resources. You can configure Event Dropping rules that will drop events just after they have been received by AccelOps, preventing these event logs from being collected and processed. Implementing these rules may require some thought to accurately set the event type, reporting device type, and event regular expression match, for example. However, dropped events do not count towards licensed Events per Second (EPS), and are not stored in the Event database. Dropped event also do not appear in reports, and do not trigger rules. You can also specify that events should be dropped but stored, so event information will be available for searches and reports, but will not trigger rules. And example of an event type that you might want to store but not have trigger any rules would be an IPS event that is a false positive.

Procedure

1. Log in to your Supervisor node.

For multi-tenant deployments you should log in to the Super/Global account if you want to set a system-wide event dropping rule. If you want to set an event-dropping rule for a specific organization, either log in as an administrator for that organization, or or log in using the Super/Global Account and then select the organization to which the rule should apply when you are creating it.

2. Go to Admin > General Settings > Event Handling.
3. Under Event Dropping Rule, click Add.
4. Next to Reporting Device, click Edit, and use the CMDB Browser to find device group or individual device that you want to create the rule for.
5. Next to Event Type, click Edit, and use the Event Type Browser to find the group of event types, or a specific event type, that you want to create the rule for.
6. If the event type you select has an Source IP or Destination IP attribute, you can enter specific IP addresses to which the rule should apply.
7. For Regex Filter, enter any regular expressions you want to use to filter the log files.

If any matches are made against your regular expression, then the event will be dropped.

8. For multi-tenant deployments, select the Organization to which the rule should apply.
9. Select the Action that should be taken when the event dropping rule is triggered.
10. Enter any Description for the rule.
11. Click Save.

Notes

1. All matching rules are implemented by AccelOps, and inter-rule order is not important. If you create a duplicate of an event dropping rule, the first rule is in effect.
2. If you leave a rule definition field blank, then that field is not evaluated. For example, leaving Event Type left blank is the same as selecting All Event Types.
3. AccelOps drops the event at the first entry point. If your deployment uses Collectors, events are dropped by the Collectors. If your deployment doesn’t use Collectors, then the event will be droppedby the Worker or Supervisor where the event is received.
4. You can use the report System Event Processing Statistics to view the statistics for dropped events. When you run the report, select AVG(Policy Dropped Event Rate(/sec) as one of the dimensions for Chart For to see events that have been dropped to this policy.