We’ve found that including routing history is invaluable when assisting network operators with their ROA planning. A few real-world examples illustrate how this context has helped: • Cold-site business continuity: Some organizations announce more specific prefixes from a different origin AS when activating a cold-site. Routing history reveals this behavior, ensuring the corresponding ROA is in place so the cold-site can operate as intended during an event. • Mobile/off-site operations: Enterprises that temporarily announce their IP space from off-site locations (e.g., conferences or remote events) often use a different origin AS. Without routing history, these temporary announcements are easily overlooked, resulting in missing ROAs. In both cases, routing history exposed announcement patterns the operators themselves had forgotten or were unaware of—and without it, they likely would have missed required ROAs. Beyond routing history, combining RIR allocation/assignment data with a visually indented prefix hierarchy helps operators quickly spot stale or unnecessary assignments and confirm the complete set of ROAs needed. The ROA Planner is modeled on an internal tool we developed to support operators in precisely these scenarios.