Bogon filtering

Bogon filtering is the practice of filtering bogons, which are bogus IP addresses of a computer network. Bogon is also an informal name for an IP packet on the public Internet that claims to be from an area of the IP address space (or network prefix or network block) reserved, but not yet allocated or delegated by the Internet Assigned Numbers Authority (IANA) or a delegated Regional Internet Registry (RIR). The areas of unallocated address space are called the bogon space.