IP Address Lookup

IP address (Internet Protocol Address) is a unique identifier for devices connected to the internet. IPv4 is 32-bit, providing about 4.3 billion addresses from 0.0.0.0 to 255.255.255.255. IPv6 is 128-bit, offering virtually infinite address space. Public IPs communicate directly on the internet, while private IPs (192.168.x.x, 10.x.x.x, 172.16-31.x.x) are translated via NAT. Dynamic IPs change each time, static IPs remain constant. IP addresses consist of network and host portions, distinguished by subnet mask.

GeoIP databases estimate geographic location from IP addresses. Services like MaxMind GeoIP2 and IP2Location provide country, city, latitude/longitude data. Accuracy is 99% at country level, 50-80% at city level. VPN, proxy, mobile networks may differ from actual location. Websites use GeoIP for automatic language setting, regional content display, fraud detection. CDNs serve content from nearest servers using GeoIP. GDPR and CCPA regulations consider IP addresses as personal data, requiring careful handling.

IP addresses can track online activities. ISPs maintain logs connecting IP addresses to users. Websites identify visitors and analyze behavior via IP. VPNs hide real IPs and display VPN server IPs for anonymity. Tor browser conceals IPs through multiple nodes. IPv6 unique per-device addresses make tracking easier. Privacy Extensions (RFC 4941) periodically change IPv6 addresses to prevent tracking. Public WiFi users share the same IP.

ISP (Internet Service Provider) can be identified from IP addresses. WHOIS databases provide IP block owner and administrative organization information. RIRs (Regional Internet Registries) include ARIN (North America), RIPE NCC (Europe), APNIC (Asia-Pacific), LACNIC (Latin America), AFRINIC (Africa). AS numbers (Autonomous System Numbers) identify network routing units. BGP routing information reveals internet paths and connectivity. IP reputation services blacklist spam and malware-sending IPs. ISPs may restrict specific services through port blocking and traffic shaping.

IPv4 addresses were exhausted at IANA level in 2011, with RIPE NCC allocating last block in 2019. NAT (Network Address Translation) connects multiple devices to one public IP, mitigating shortage. CGNAT (Carrier-Grade NAT) performs NAT at ISP level, making port forwarding difficult. IPv6 offers 340 undecillion (2^128) addresses, essential for IoT era. Dual stack supports both IPv4 and IPv6 simultaneously, with tunneling (6to4, Teredo) carrying IPv6 over IPv4 networks. As of 2023, over 40% of Google users globally access via IPv6.

IP address lookup tools serve various purposes. Website administrators analyze visitor IPs for country statistics. Security personnel verify suspicious IP origins to block attacks. Email header IPs track spam sources. VPN users confirm real IPs are hidden after connection. DNS record lookups verify domain IP addresses. Reverse DNS (PTR) finds domains from IPs. Network troubleshooting uses traceroute to check route IPs. API services provide localized content based on IP addresses.