In an IDS deployment, what is the primary purpose of alert correlation?

To reduce the volume of alerts by grouping related events into a single incident

To automatically block malicious IP addresses at the firewall

To encrypt alert data before it is stored in the SIEM

To increase the sensitivity of individual signatures so that more alerts are generated

An analyst is investigating an IDS alert that was triggered by a single packet containing a known exploit signature. However, the analyst suspects the attack may have been fragmented or encoded to evade detection. Which action would best help the analyst determine if the attack was successful?

Check the IDS logs for other alerts from the same source IP.

Disable the signature that triggered the alert to prevent future false positives.

Increase the IDS sensitivity to catch more variations of the exploit.

Review the full packet capture and reassemble the session to see the complete payload.

A company's IDS generates a high volume of alerts for a legitimate internal application that uses unusual but benign network behavior. The analyst wants to reduce false positives without losing visibility into real attacks against that application. Which tuning action is most appropriate?

Create a custom rule that excludes the application's known benign traffic patterns.

Raise the global alert threshold for all signatures.

Disable the signature that is causing the alerts.

Move the IDS sensor to a different network segment.

An analyst notices that an IDS is generating alerts for a legitimate backup process that runs every night and transfers large amounts of data between two internal servers. The analyst wants to reduce false positives without losing visibility into other traffic from these servers. What is the most appropriate tuning action?

Add both servers to the IDS ignore list so no alerts are generated for them.

Increase the global alert threshold for all traffic to reduce the number of alerts generated.

Disable the IDS rules that match the backup protocol to stop the alerts entirely.

Create a suppression rule that filters alerts for the specific source and destination IP pair during the scheduled backup window.

An organization has an IDS that is generating a high number of false positives due to a misconfigured application. The analyst wants to reduce false positives but is concerned about missing a real attack that uses the same pattern. The analyst has limited time to tune the IDS. Which approach is most effective?

Deploy a second IDS to cross-check alerts.

Disable the signature that is causing the false positives.

Create a targeted suppression rule for the specific application's traffic.

Raise the global alert threshold.

GIAC Certified Intrusion Analyst

Domain 3Objective 2

Advanced IDS Concepts GCIA Practice Questions (Page 5)

Part of the IDS Concepts and Architecture domain, which makes up ~18% of our current practice bank. GIAC (SANS) does not publish an official question count, but from its 240-minute exam (~95–160 total, ~17–29 in this domain), expect 6–10 from this objective — we provide 26 practice questions to prepare you well beyond it. (estimate)

26questions here

6free pages

1concept

Questions 21–25

21foundation · easy
In an IDS deployment, what is the primary purpose of alert correlation?
Select an answer first
22application · medium
An analyst is investigating an IDS alert that was triggered by a single packet containing a known exploit signature. However, the analyst suspects the attack may have been fragmented or encoded to evade detection. Which action would best help the analyst determine if the attack was successful?
Select an answer first
23application · medium
A company's IDS generates a high volume of alerts for a legitimate internal application that uses unusual but benign network behavior. The analyst wants to reduce false positives without losing visibility into real attacks against that application. Which tuning action is most appropriate?
Select an answer first
24application · medium
An analyst notices that an IDS is generating alerts for a legitimate backup process that runs every night and transfers large amounts of data between two internal servers. The analyst wants to reduce false positives without losing visibility into other traffic from these servers. What is the most appropriate tuning action?
Select an answer first
25expert · hard
An organization has an IDS that is generating a high number of false positives due to a misconfigured application. The analyst wants to reduce false positives but is concerned about missing a real attack that uses the same pattern. The analyst has limited time to tune the IDS. Which approach is most effective?
Select an answer first

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Advanced IDS Concepts GCIA Practice Questions (Page 5)

Questions 21–25

In an IDS deployment, what is the primary purpose of alert correlation?

An analyst is investigating an IDS alert that was triggered by a single packet containing a known exploit signature. However, the analyst suspects the attack may have been fragmented or encoded to evade detection. Which action would best help the analyst determine if the attack was successful?

A company's IDS generates a high volume of alerts for a legitimate internal application that uses unusual but benign network behavior. The analyst wants to reduce false positives without losing visibility into real attacks against that application. Which tuning action is most appropriate?

Keep studying — IDS Concepts and Architecture