GCIA GIAC Certified Intrusion Analyst Practice Test
Build your confidence for GCIA GIAC Certified Intrusion Analyst. Practice the concepts, understand the answers, and strengthen your knowledge one question at a time.
Try a sample questionExam overview and details
The GIAC Certified Intrusion Analyst (GCIA) certification is a premier, industry-recognized credential validating an individual's advanced skills in network security monitoring, intrusion detection, and incident response. Administered by the Global Information Assurance Certification (GIAC), a SANS Institute affiliate, the GCIA focuses on the deep technical analysis of network traffic to identify, respond to, and defend against sophisticated cyber threats. Earning the GCIA demonstrates mastery of core competencies including the creation and tuning of IDS/IPS signatures (particularly Snort rules), comprehensive TCP/IP protocol analysis, network forensics, and log analysis using tools like Wireshark. It signifies that the holder can move beyond alert monitoring to perform proactive threat hunting and detailed incident reconstruction. This certification is highly valued by employers in Security Operations Centers (SOCs), Computer Security Incident Response Teams (CSIRTs), and threat intelligence units, as it proves the practical ability to defend critical network infrastructure.
Sample Questions
Choose an answer and explore the explanation to see how practice works.
During GCIA packet-analysis review, Zeek conn.log shows a workstation making HTTPS connections to one new IP every 61 seconds with 900 bytes out and 700 bytes back. What is the BEST interpretation or next analyst action?
While performing traffic analysis with Wireshark on a potentially compromised workstation, you observe several TCP/IP protocol anomalies. Which observations would be considered valid indicators of suspicious network behavior warranting further investigation? (Select all that apply)
During GCIA packet-analysis review, A capture shows IPv4 protocol number 1 in the header after Ethernet decoding. What is the BEST interpretation or next analyst action?
During GCIA packet-analysis review, A SYN includes MSS, SACK permitted, window scale, and timestamp options in an unusual order for the claimed OS. What is the BEST interpretation or next analyst action?
During GCIA packet-analysis review, A span port misses short microbursts even though average utilization is low. What is the BEST interpretation or next analyst action?
Career Opportunities & Salary
Exam insights and study advice
Achieving the GCIA certification is a significant career differentiator in the cybersecurity field. It provides tangible proof of high-demand, hands-on technical skills that are critical for roles such as Intrusion Analyst, Network Forensic Analyst, and Threat Hunter. The certification is recognized globally by government agencies, military organizations, and leading corporations as a benchmark for intrusion analysis expertise. Holding a GCIA not only validates your technical proficiency but also signals a deep commitment to the cybersecurity profession, directly enhancing your credibility, marketability, and potential for career advancement and increased compensation in a competitive job market.
What this exam covers
01Concepts of TCP/IP and the Link Layer
Topics
- Concepts of TCP/IP and the Link Layer
Learning objectives
- Concepts of TCP/IP and the Link Layer: Demonstrate understanding of the TCP/IP communications model and link layer operations
02Fragmentation
Topics
- Fragmentation
Learning objectives
- Fragmentation: Demonstrate understanding of how fragmentation works, and how to identify fragmentation and fragmentation-based attacks in packet captures
03Fundamentals of Traffic Analysis and Application Protocols
Topics
- Application Protocols
Learning objectives
- Application Protocols: Demonstrate knowledge and skill relating to application layer protocol dissection and analysis
04IP Headers
Topics
- IP Headers
Learning objectives
- IP Headers: Demonstrate the ability to dissect IP packet headers and analyze them for normal and anomalous values that may point to security issues
05IPv6
Topics
- IPv6
Learning objectives
- IPv6: Demonstrate knowledge of IPv6 and how it differs from IPv4
06Network Traffic Forensics and Monitoring
Topics
- Network Forensics and Traffic Analysis
Learning objectives
- Network Forensics and Traffic Analysis: Demonstrate competence in analyzing data from multiple sources (e.g., full packet capture, netflow, log files) to identify normal and malicious behaviors
07Open-Source Intrusion Detection Systems (IDS): Snort and Zeek
Topics
- IDS Fundamentals and Network Architecture
- Intrusion Detection System Rules
Learning objectives
- IDS Fundamentals and Network Architecture: Demonstrate knowledge of fundamental IDS concepts, such as network architecture options and benefits/weaknesses of common IDS systems
- Intrusion Detection System Rules: Create effective IDS rules to detect varied types of malicious activity
08Packet Engineering
Topics
- Packet Engineering
Learning objectives
- Packet Engineering: Demonstrate knowledge relating to packet crafting and manipulation
09SiLK and Other Traffic Analysis Tools
Topics
- SiLK and Other Traffic Analysis Tools
Learning objectives
- SiLK and Other Traffic Analysis Tools: Demonstrate an understanding of SiLK and other tools to perform network traffic and flow analysis
10TCP
Topics
- TCP
Learning objectives
- TCP: Demonstrate understanding of the TCP protocol and the ability to discern between typical and anomalous behavior
11Tcpdump Filters
Topics
- Tcpdump Filters
Learning objectives
- Tcpdump Filters: Demonstrate ability to craft tcpdump filters that match on given criteria
12UDP and ICMP
Topics
- UDP and ICMP
Learning objectives
- UDP and ICMP: Demonstrate understanding of the UDP and ICMP protocols and the ability to discern between typical and anomalous behavior
13Wireshark Fundamentals
Topics
- Wireshark Fundamentals
Learning objectives
- Wireshark Fundamentals: Demonstrate ability to use Wireshark to analyze typical and malicious network traffic