A fire district is building the SD-Access underlay and wants a stable IGP. Which prefix policy correctly reflects underlay design intent?
Select an answer to reveal the explanation.
Short Explanation
The underlay is the highway system; it should know road IDs, not every passenger’s home address. Keep infrastructure and locator prefixes in the IGP, and let the overlay track user endpoint subnets. Dumping every user subnet into the underlay makes the highway map noisy and brittle.
Full Explanation
SD-Access underlays provide IP reachability between fabric locators (edges, borders, control-plane nodes) and should remain relatively stable and small. Endpoint/user subnets belong in the overlay mapping system, not as widespread redistributed prefixes in the underlay IGP. Redistributing noisy user spaces into the underlay defeats overlay separation and harms convergence and clarity.