Cisco Certified Internetwork Expert (CCIE) Practice Test 2025 – Your Complete All-in-One Guide to Exam Success!

The correct choice is LISP, which stands for Locator/ID Separation Protocol. This technology is specifically designed to address scalability issues related to IP address routing within large networks. LISP separates the concepts of location and identity in networking, allowing for more flexible network configurations and facilitating the creation of overlay networks.

Overlay networks are virtual networks built on top of existing physical networks, and LISP provides a robust framework for these applications. Using LISP, network operators can create logical abstractions that improve traffic management, mobility, and multi-homing capabilities while ensuring that the underlying infrastructure remains efficient and unaffected by the changes made in the overlay.

In contrast, other technologies listed, such as OpFlex, MPLS, and Ethernet, do not primarily focus on providing a framework for overlay networks. OpFlex is more concerned with policy enforcement in software-defined networking, MPLS is primarily used for efficient packet forwarding and traffic engineering within physical networks, and Ethernet functions as a fundamental data link layer protocol without the inherent capabilities needed for overlay network applications.