Certified Information Systems Security Professional (CISSP) Practice Exam 2025 – All-in-One Guide to Mastering Your Certification!

Layer 2 Forwarding (L2F) is a tunneling protocol designed to support virtual private networks (VPNs) and allows for the encapsulation of data packets in a manner that can traverse different networks while maintaining the integrity of the Layer 2 information. It operates at the data link layer of the OSI model, enabling the transport of various types of network traffic across IP networks without losing the original data link layer protocols.

This protocol is significant in scenarios where VPNs require a connection to be established over an IP network while preserving the characteristics of the original network frame. L2F supports multiple protocols and provides a way for clients to connect securely to a service provider's network, emphasizing the importance of encapsulating Layer 2 frames for privacy and efficiency.

The other options refer to terms that are not standard or widely recognized in the context of tunneling protocols or data link layer operations. Layer 2 Framework, Layer 2 Functionality, and Layer 2 Filtering do not specifically describe a protocol or standard associated with tunneling like L2F does. Thus, Layer 2 Forwarding stands out as the accurate term related to this topic.