- Internet Corporation for Assigned Names and Numbers (ICANN)
- Allocates large blocks to Regional Internet Registries
- Regional Internet Registries (RIRs)
- E.g., ARIN (American Registry for Internet Numbers)
- Allocates to ISPs and large institutions
- Internet Service Providers (ISPs)
- Allocate address blocks to their customers
- Who may, in turn, allocate to their customers…