Adresse IP Publique

How Public IPs Are Allocated

Public IP addresses flow down a hierarchy. IANA manages the master IPv4Internet Protocol version 4. The fourth revision of IP using 32-bit addresses (e.g., 192.168.1.1), providing approximately 4.3 billion unique addresses. Still the most widely used internet protocol despite address exhaustion. and IPv6Internet Protocol version 6. The successor to IPv4 using 128-bit addresses (e.g., 2001:0db8::1), providing a virtually unlimited address space of 3.4 x 10^38 addresses. Designed to solve IPv4 address exhaustion. pools, delegating large blocks to five Regional Internet Registries (RIRs): ARIN (North America), RIPE NCC (Europe/Middle East), APNIC (Asia-Pacific), LACNIC (Latin America), and AFRINIC (Africa). RIRs allocate smaller blocks to Internet Service Providers (ISPs) and large organizations, who assign individual addresses to customers and services.

Every public IP is associated with an Autonomous System — an independently operated network identified by an AS Number (ASN). BGP routes packets between ASes using public IP prefixes as destinations.

Static vs. Dynamic Public IPs

Consumer ISPs typically assign dynamic public IPs via DHCPDynamic Host Configuration Protocol. A network protocol that automatically assigns IP addresses, subnet masks, gateways, and DNS servers to devices when they join a network., changing them periodically or on reconnection. Business-grade connections often provide one or more Static IP AddressA permanently assigned IP address that does not change over time. Commonly used for servers, printers, and network devices that need a consistent address for reliable access. addresses. Hosting providers assign static public IPs to servers since their DNS records must remain stable — a server's A RecordA DNS record that maps a domain name to an IPv4 address (e.g., example.com -> 93.184.216.34). The most fundamental DNS record type for resolving domain names to IP addresses. can't be chasing a moving address.

IP Geolocation and Reputation

Public IPs carry metadata: geolocation databases map them to approximate physical locations (country, city, ISP). This mapping is maintained by commercial providers and used for content localization, access control, and fraud detection. The accuracy degrades at the city level — large NATNetwork Address Translation. A method of remapping private IP addresses to a single public IP address (and vice versa) at a router, allowing multiple devices to share one public IP. A key technique for mitigating IPv4 address exhaustion. deployments and anycast infrastructure mean the geolocation of a public IP may reflect the ISP's network hub rather than the user's actual location.

IP reputation databases track whether a public IP has been associated with spam, malware, or abuse. Use IP Blacklist Check to check an IP against major blocklists, or IP Lookup for geolocation and ASN details.