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350-401 · Question #78

Which technology provides a secure communication channel for all traffic at Layer 2 of the OSI model?

The correct answer is A. MACsec. MACsec (IEEE 802.1AE) operates at Layer 2 (Data Link Layer) of the OSI model, providing hop-by-hop encryption and authentication of Ethernet frames between directly connected devices - making it the only true Layer 2 security protocol listed. IPsec (B) operates at Layer 3 (Networ

Submitted by ngozi_ng· Mar 6, 2026Security

Question

Which technology provides a secure communication channel for all traffic at Layer 2 of the OSI model?

Options

  • AMACsec
  • BIPsec
  • CSSL
  • DCisco Trustsec

How the community answered

(36 responses)
  • A
    89% (32)
  • B
    6% (2)
  • C
    3% (1)
  • D
    3% (1)

Explanation

MACsec (IEEE 802.1AE) operates at Layer 2 (Data Link Layer) of the OSI model, providing hop-by-hop encryption and authentication of Ethernet frames between directly connected devices - making it the only true Layer 2 security protocol listed. IPsec (B) operates at Layer 3 (Network Layer), securing IP packets rather than Ethernet frames. SSL (C) works at the Application/Transport layer (Layer 5-7 depending on the model), securing application data like web traffic. Cisco TrustSec (D) is a Cisco-proprietary framework that uses Security Group Tags (SGTs) for policy-based access control - while it can leverage MACsec for encryption, TrustSec itself is a broader architecture, not a standalone Layer 2 encryption technology.

Memory Tip: Think "MAC = Layer 2" - just like MAC addresses live at Layer 2, MACsec secures traffic at that same layer. If the answer involves anything with "MAC," think Data Link Layer.

Topics

#MACsec#Layer 2 Security#OSI Model#Data Link Layer

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