5 Quick Checks: Is Your IP Space Actually Being Used?
Most organisations hold address space they cannot account for. These five checks reveal dormant inventory — and the risk hiding in it.
1. Compare registry vs reality
Pull your RIR records and cross-reference with routing tables. Space that is allocated but never announced in BGP is a candidate for dormancy.
2. Probe common ports
Passively scan your blocks for answers on 80, 443, 53 and 22. A whole /24 with zero responses is not "quiet" — it is dark.
3. Check reputation feeds
Search your ranges in abuse and blacklist databases. Clean silence is one thing; silence with a spam history is a liability.
4. Review transfer records
Registry transfer history shows when space changed hands. Old, stable ownership plus no usage usually means dormant inventory.
5. Ask your own network team
Last resort, but honest: many allocations survive internal reorganisations nobody remembers. A documented audit beats a guess — and IPDORM automates the measurement part.