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Explained the attack fine, ARP has no authentication so an attacker can broadcast fake MAC-to-IP mappings and redirect traffic.
Start by defining ARP poisoning as a man-in-the-middle attack that exploits the lack of authentication in ARP. Then, discuss mitigation strategies at different layers, emphasizing practical defenses like Dynamic ARP Inspection and static ARP entries, and tie them to system design trade-offs such as security vs. complexity.
Pro tip: Mention that while ARP poisoning is a Layer 2 attack, its impact can be mitigated at higher layers through encryption and network segmentation, showing a holistic security mindset. Also, highlight that at scale, automated monitoring and anomaly detection are crucial, as manual static ARP entries are impractical.
Explain that ARP poisoning is a cyberattack where an attacker sends falsified ARP messages to link their MAC address with the IP of a legitimate host, enabling traffic interception or denial of service.
Describe how ARP works without authentication, allowing attackers to broadcast spoofed replies and poison ARP caches of other devices on the same subnet.
List and explain defenses such as Dynamic ARP Inspection (DAI), DHCP snooping, static ARP entries, port security, and network segmentation. Mention encryption (e.g., TLS, VPNs) to protect data even if ARP is poisoned.
Analyze the trade-offs of each mitigation: static ARP is secure but unscalable; DAI requires managed switches and configuration; encryption adds overhead but provides end-to-end security.
Relate to large-scale systems like Pinterest: emphasize defense-in-depth, monitoring for anomalies, and designing networks with segmentation and zero-trust principles.
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