Understanding, Preventing, And Defending Agains... Apr 2026

While most security focuses on Layers 3 through 7, the Data Link Layer (Layer 2) remains a critical yet often overlooked vulnerability surface. This paper outlines the primary attack vectors—including MAC flooding, DHCP spoofing, and VLAN hopping—and provides a framework for multi-layered defense strategies in switched Ethernet environments. 1. Common Layer 2 Vulnerabilities

Disable unused ports and assign them to an isolated, non-routed VLAN. Disable auto-trunking (DTP) on user-facing ports. Understanding, Preventing, and Defending Agains...

Limit the number of MAC addresses allowed per port to prevent CAM table overflows. VLAN Hardening: Never use VLAN 1 for user traffic or management. While most security focuses on Layers 3 through

In modern environments, particularly those involving , defense-in-depth is essential: particularly those involving