Glossary

IPv4

IPv4 is the original 32-bit internet addressing scheme, written as four dotted numbers, now exhausted and supplemented by IPv6.

IPv4 is the fourth version of the Internet Protocol and still the most widely deployed addressing scheme. An IPv4 address is 32 bits, written as four decimal octets separated by dots, such as 93.184.216.34.

The exhaustion problem

32 bits allow roughly 4.3 billion addresses — far fewer than today's connected devices. The free pool has been depleted, which drove the adoption of ipv6 and workarounds like NAT and Carrier-Grade NAT, where many users share one public address.

Why it matters for hosting

Because public IPv4 addresses are scarce and valuable, dedicated IPv4 addresses sometimes carry an extra cost. Shared hosting frequently puts hundreds of sites behind a single IPv4 via the HTTP Host header and SNI.

Every IPv4 host is reached through an a-record, and the address can be traced to its owner via asn and whois. Publishing an aaaa-record for ipv6 alongside it future-proofs reachability.

See also

IPv6 IPv6 is the 128-bit internet addressing scheme that replaces scarce IPv4, offering a virtually unlimited supply of addresses. IP Address An IP address is the unique numeric label assigned to each device on a network, used to route data to the right destination across the internet. A Record An A record is the DNS entry that maps a domain name to an IPv4 address, telling browsers exactly which server hosts the website. ASN (Autonomous System Number) An ASN is a unique number identifying a network of IP ranges under one operator, used by BGP to route traffic across the internet.

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