IPv6 Address Planning

Glossary

GENTEEL, adj. Refined, after the fashion of a gent. Observe with care, my son, the distinction I reveal: A gentleman is gentle and a gent genteel. Heed not the definitions your “Unabridged” presents, For dictionary makers are generally gents.

— Ambrose Bierce The Devil’s Dictionary (1911)

Allocation

(As compared with assignment) Formally, the apportionment of an IP address prefix to a RIR by IANA or to a LIR by a RIR. Informally, any allotment of an IP prefix which will be further subnetted for smaller allotments (referred to as assignments).

Assignment

Formally, the apportionment of an IP address prefix by an ISP to an end-user, but sometimes used interchangeably with allocation and/or to mean any allotted prefix.

Bogon

An invalid (i.e., bogus) routing prefix that should never appear in the global routing table. Perhaps the most well-known example of a bogon is RFC 1918, or private, IPv4 address space. Addresses from bogon prefixes can be used by hackers and miscreants to spoof source addresses in malicious packets and therefore should be filtered, ideally inbound and outbound, at an organization’s network edge.

Bisection

An IP allocation method (preferred by service providers and RIRs) that leaves the maximum amount of space between each prefix assignment (while still providing enough prefixes of the desired subnet size for immediate use). Subsequent allocations may evenly divide the space remaining between original assignments. Bisection is better suited ...