MAC Flooding

Summary

MAC Flooding is a network-based attack targeting Ethernet switches by overwhelming their MAC address tables with fake addresses, causing the switch to behave like a hub and enabling attackers to intercept network traffic.

Key Characteristics

• Involves flooding a switch’s MAC address table with numerous fake MAC addresses.
• Forces the switch to enter a fail-open mode, broadcasting traffic to all ports.
• Allows attackers to perform traffic sniffing and potentially launch man-in-the-middle attacks.
• Typically targets Layer 2 network infrastructure to compromise data confidentiality.
• Exploits limitations in switch hardware and software MAC address table capacity.

Defensive Controls

• Implement port security features to limit the number of MAC addresses learned per port.
• Enable dynamic ARP inspection and DHCP snooping to prevent spoofing.
• Use VLAN segmentation to isolate sensitive network segments.
• Regularly monitor network traffic for unusual MAC address activity.
• Deploy intrusion detection systems (IDS) to detect abnormal flooding behavior.

Related Security Solutions

Network access control (NAC) systems, managed switches with port security capabilities, intrusion detection and prevention systems (IDPS), and network segmentation technologies help mitigate MAC Flooding attacks by controlling device access and monitoring network behavior.