What Are Two Evasion Techniques That Are Used By Hackers? (Choose Two)

The CCNA 200-301 exam has a total duration of 120 minutes (2 hours). This time is allotted to complete all exam questions, which typically range between 100 to 120 multiple-choice and simulation-based questions. Proper time management is essential to ensure all questions are answered within the time limit.

Tech Professionals

11 April 2025

Cisco

What Are Two Evasion Techniques That Are Used By Hackers? (Choose Two)

Introduction To CCNA 200-301 Exam Duration

In the ever-evolving landscape of cybersecurity, hackers are constantly devising new and sophisticated methods to bypass security measures. Understanding these techniques is crucial for anyone looking to bolster their defenses, especially those pursuing certifications like the CCNA 200-301. While the CCNA 200-301 exam duration is a common query among aspiring network professionals, it's equally important to delve into the practical aspects of network security. Today, we'll explore two prominent evasion techniques hackers employ: fragmentation attacks and source IP address spoofing.

The Importance of Practical Knowledge in Network Security

Before diving into the specifics, it's essential to acknowledge the significance of practical knowledge alongside theoretical understanding. Certifications like the CCNA 200-301, offered by platforms like Study4Pass, lay a solid foundation. However, real-world scenarios often require a deeper comprehension of how attacks unfold. Knowing the "CCNA 200-301 exam duration" is only the first step; mastering the concepts behind network security is what truly matters.

1. Fragmentation Attacks: Bypassing Security Through Packet Division

Fragmentation attacks exploit the way network protocols handle large packets. When data exceeds the Maximum Transmission Unit (MTU) of a network, it's broken down into smaller fragments. Hackers manipulate this process to evade detection and infiltrate systems.

How Fragmentation Attacks Work:

Packet Fragmentation: TCP/IP protocols allow data to be fragmented into smaller packets for transmission.
Manipulating Fragments: Hackers craft malicious fragments with overlapping or conflicting offsets, causing the target system to reassemble them incorrectly.
Bypassing Firewalls and Intrusion Detection Systems (IDS): By sending small, seemingly innocuous fragments, attackers can slip past security devices that rely on inspecting complete packets.
Reassembly Issues: The target system, upon reassembling the fragments, may execute malicious code or be vulnerable to buffer overflow attacks.

Example Scenario:

Imagine a firewall that filters packets based on specific Study4pass signatures. A hacker can fragment a malicious payload into small packets, each containing a portion of the signature. The firewall, analyzing individual fragments, might not detect the complete signature. However, when the target system reassembles the fragments, the malicious payload is reconstructed and executed.

Why Fragmentation Attacks Are Effective:

Security devices often lack the resources to reassemble and analyze every fragmented packet in real-time.
The complexity of packet reassembly can lead to vulnerabilities in the target system's operating system or network stack.
Attackers can use various fragmentation techniques, such as overlapping fragments or tiny fragments, to further obfuscate their malicious intent.

Mitigation Strategies:

Implement robust packet reassembly mechanisms: Ensure that network devices can properly reassemble fragmented packets and detect anomalies.
Configure firewalls and IDS to analyze fragmented packets: Enable features that allow security devices to inspect and reassemble fragments before making filtering decisions.
Apply security patches and updates: Keep operating systems and network devices updated to address known vulnerabilities related to packet fragmentation.
Use deep packet inspection (DPI): DPI allows for more thorough analysis of packet contents, including fragmented packets.

2. Source IP Address Spoofing: Masking the Attacker's Identity

Source IP address spoofing involves forging the source IP address in network packets to conceal the attacker's true location and identity. This technique is often used in conjunction with other attacks, such as Distributed Denial of Service (DDoS) attacks.

How Source IP Address Spoofing Works:

Forging IP Addresses: Hackers use tools or custom scripts to create packets with fabricated source IP addresses.
Bypassing Access Control Lists (ACLs): Some systems rely on ACLs to filter traffic based on source IP addresses. Spoofing allows attackers to bypass these controls.
Launching DDoS Attacks: By spoofing the source IP addresses of numerous compromised devices, attackers can overwhelm a target system with traffic, making it difficult to trace the attack back to the original source.
Evading Intrusion Detection: By making the attack appear to originate from a trusted network, attackers can avoid triggering alarms.

Example Scenario:

In a DDoS attack, a hacker might spoof the source IP addresses of thousands of botnet devices. The target system receives a flood of traffic from various seemingly legitimate sources, making it nearly impossible to filter out the malicious packets. This can lead to service disruptions and system crashes.

Why Source IP Address Spoofing Is Effective:

IP address spoofing is relatively easy to implement with readily available tools.
The stateless nature of the IP protocol makes it challenging to verify the authenticity of source IP addresses.
Distributed attacks make it difficult to trace the attack back to a single source.

Mitigation Strategies:

Implement ingress filtering: Configure network devices to block packets with source IP addresses that do not belong to the local network.
Use Reverse Path Forwarding (RPF): RPF verifies that incoming packets are arriving from the expected interface, helping to detect spoofed IP addresses.
Deploy strong authentication mechanisms: Implement multi-factor authentication and other strong authentication methods to prevent unauthorized access.
Monitor network traffic for anomalies: Use intrusion detection systems and security information and event management (SIEM) tools to detect suspicious traffic patterns.
Use TCP sequence number randomization: This makes it harder for attackers to predict the sequence numbers used in TCP connections, which can be exploited in spoofing attacks.

Study4Pass and CCNA 200-301 Preparation

Understanding evasion techniques like fragmentation attacks and source IP address spoofing is vital for network security professionals. Platforms like Study4Pass provide valuable resources for preparing for the CCNA 200-301 Certification and gaining practical knowledge. While the "CCNA 200-301 exam duration" is a crucial aspect of exam preparation, the real value lies in mastering the concepts and skills needed to secure networks effectively.

By focusing on practical examples and real-world scenarios, Study4Pass helps students bridge the gap between theory and practice. This comprehensive approach ensures that aspiring network professionals are not only prepared for the exam but also equipped to handle the challenges of a dynamic cybersecurity landscape.

Conclusion

Evasion techniques like fragmentation attacks and source IP address spoofing pose significant threats to network security. Understanding how these attacks work and implementing effective mitigation strategies is crucial for protecting systems and data. By combining theoretical knowledge with practical experience, as facilitated by platforms like Study4Pass, aspiring network professionals can build a strong foundation in cybersecurity and excel in their careers