BGP

Chapter 4. IP Address Space and AS Numbers

All IP addresses aren’t created equal. Which kind of IP addresses to announce over BGP is an important decision: it has a large impact on the reachability of your network, and it also has important financial consequences. The main decision is whether to keep using ISP-based addresses or to apply for an independent address range of your own. This poses an important question: where do IP addresses come from, if not from your ISP?

The Internet Assigned Numbers Authority (IANA) is responsible for assigning the protocol numbers used on the Internet. This includes IP addresses and AS numbers, but the IANA has delegated these activities to three Regional Internet Registries (RIRs):

APNIC: http://www.apnic.net

The Asia-Pacific Network Information Centre in Brisbane, Australia, serves most of Asia, Australia, and the Pacific.

ARIN: http://www.arin.net

The American Registry for Internet Numbers in Chantilly, Virginia, United States, serves North America.

RIPE NCC: http://www.ripe.net

The Réseaux IP Européens Network Coordination Centre in Amsterdam, The Netherlands, serves Europe, the Middle East, and the former Soviet Union countries.

Work is currently underway to establish two additional RIRs: one serving the region of Latin America, and the other serving continental Africa. For the time being, ARIN serves Latin America, the Caribbean, and Africa south of the Sahara, and the RIPE NCC serves Africa north of the Sahara.

In turn, the RIRs delegate responsibility ...