IPv4 Glossary
Key terms and definitions for IPv4 addressing, networking protocols, RIR operations, and the IPv4 transfer market.
AFRINIC
The Regional Internet Registry for Africa, responsible for allocating IP address resources in the African region.
APNIC
The Regional Internet Registry for the Asia Pacific region, managing IP address allocation across Asia and Oceania.
ARIN
The American Registry for Internet Numbers, the RIR responsible for IP address management in the United States, Canada, and several Caribbean and North Atlantic islands.
ASN (Autonomous System Number)
A unique identifier assigned to a network or group of networks under a single administrative domain for BGP routing on the internet.
BGP (Border Gateway Protocol)
The routing protocol used to exchange routing information between autonomous systems on the internet, determining how IP traffic flows between networks.
Blacklist
A database of IP addresses identified as sources of spam, malware, or other malicious activity. Being blacklisted can affect email deliverability and network reputation.
Check IP Blacklist StatusCIDR (Classless Inter-Domain Routing)
A method of IP address allocation that replaces the older class-based system, using slash notation (e.g., /24) to define network size.
Due Diligence
The investigation and verification process performed before an IPv4 transaction, including blacklist checks, BGP history review, and ownership verification.
Escrow
A financial arrangement where a third party holds funds during a transaction until all conditions are met, commonly used in IPv4 purchases for buyer and seller protection.
Geofeed
An RFC 8805 standard file format that allows IP address holders to publish geolocation data for their IP ranges, helping improve IP geolocation accuracy.
Geofeed Generator ToolInter-RIR Transfer
The transfer of IPv4 addresses between organizations registered under different Regional Internet Registries.
Intra-RIR Transfer
The transfer of IPv4 addresses between organizations registered under the same Regional Internet Registry.
IPv4 (Internet Protocol version 4)
The fourth version of the Internet Protocol, using 32-bit addresses (e.g., 192.168.1.1). The global IPv4 address pool has been exhausted since 2011, creating a secondary market for trading addresses.
Browse IPv4 MarketplaceIPv4 Broker
A company or individual that facilitates IPv4 address transactions between buyers and sellers, handling contracts, due diligence, and RIR transfer processes.
About ipv4.centerIPv4 Exhaustion
The depletion of the global pool of unallocated IPv4 addresses. All five RIRs have exhausted their free pools, making the secondary market the primary source for acquiring IPv4 space.
IPv6 (Internet Protocol version 6)
The successor to IPv4, using 128-bit addresses to provide a virtually unlimited address space. IPv6 adoption is growing but IPv4 remains essential for most internet operations.
LACNIC
The Regional Internet Registry for Latin America and the Caribbean, responsible for IP address allocation in the region.
LOA (Letter of Authorization)
A formal document authorizing a lessee to use and announce specific IPv4 address blocks, typically provided in IPv4 lease agreements.
Lease IPv4 AddressesPrefix
An IPv4 address block defined by a network address and subnet mask, expressed in CIDR notation (e.g., 192.0.2.0/24 represents 256 addresses).
RIR (Regional Internet Registry)
Organizations responsible for managing and allocating IP address resources in specific geographic regions. The five RIRs are RIPE NCC, ARIN, APNIC, LACNIC, and AFRINIC.
RIPE NCC
Réseaux IP Européens Network Coordination Centre, the RIR for Europe, the Middle East, and parts of Central Asia. RIPE NCC handles the most active IPv4 transfer market.
ROA (Route Origin Authorization)
A cryptographically signed object in RPKI that authorizes an autonomous system to originate routes for specific IP prefixes, helping prevent route hijacking.
RPKI (Resource Public Key Infrastructure)
A security framework for internet routing that provides a way to connect IP address blocks to their legitimate holders using digital certificates.
Subnet
A logical subdivision of an IP network, identified by a range of IP addresses. Common subnet sizes include /24 (256 IPs), /23 (512 IPs), /22 (1,024 IPs), and /16 (65,536 IPs).
View Subnet PricingTransfer Policy
The rules and procedures established by each RIR governing how IPv4 address blocks can be transferred between organizations.
Understanding the IPv4 Ecosystem
The IPv4 address market involves multiple stakeholders, registries, and technical protocols. This glossary covers the essential terminology you need to navigate it confidently.
Ready to Enter the IPv4 Market?
Now that you know the terminology, explore our marketplace to buy, sell, or lease IPv4 addresses with confidence.