A township board asks why user VLANs in SD-Access terminate at the fabric edge instead of spanning through the campus core. What is the correct explanation?
Select an answer to reveal the explanation.
Short Explanation
Old campuses stretched VLANs like holiday lights through the core—pretty until one bulb floods everything. In fabric, the edge is where that Layer-2 neighborhood stops and routing into the overlay begins. User subnets live at the edge; the core stays a transport, not a giant broadcast domain.
Full Explanation
In Cisco SD-Access, fabric edge nodes terminate endpoint VLANs/SVIs (or equivalent host onboarding constructs) and encapsulate traffic into the overlay. That makes the edge the L2/L3 demarc for user subnets rather than stretching VLANs across the campus core. The underlay provides IP transport between locators; VXLAN/LISP handle overlay forwarding without classic end-to-end VLAN sprawl.