Free tool
Bogon Advertisement Checker
Detect bogon prefixes and bogon ASNs announced by or seen in paths of a network, plus over-specific announcements.
About this tool
Bogons are prefixes and ASNs that should never appear in the global routing table — private (RFC 1918), shared CGNAT space, documentation ranges, reserved and private ASNs. Announcing or propagating them is a misconfiguration and a security risk.
Lookups are rate-limited and logged for abuse prevention. Results reflect public routing data and registries.