If a site cutover, mail change, or API move is still resolving the old address, this guide shows the current Ubuntu DNS flush command, the legacy alias, and how to check whether another local cache is actually the problem.
Old browser-console snippets that click Cloudflare dashboard buttons are obsolete and risky on live zones. This version shows the safer modern path: Cloudflare's built-in bulk delete, official DNS APIs, and a review-first workflow that works for real client cleanup projects.