IP Geolocation Lookup

The IP Geolocation Lookup tool maps IP addresses to physical locations and network ownership information. Every device connected to the internet has an IP address that can be traced to an approximate geographic location using geolocation databases maintained by organizations like MaxMind, IP2Location, and regional internet registries (RIRs). This tool provides country, region, city, coordinates, ISP, and Autonomous System Number (ASN) information for any IP address. Whether you're analyzing web traffic, investigating security incidents, implementing geo-fencing, or understanding your user base, IP geolocation provides valuable contextual information about network endpoints.

IP geolocation maps IP addresses to physical locations using databases compiled from various sources including WHOIS records, BGP routing data, user submissions, and commercial partnerships.

How IP Geolocation Works:

• Database Compilation: Vendors aggregate data from multiple sources
  • Regional Internet Registries (ARIN, RIPE, APNIC, LACNIC, AFRINIC)
  • WHOIS records showing registrant location
  • BGP routing tables and AS path information
  • Latency measurements (trilateration from known points)
  • User-submitted location data (mobile apps, web services)
  • Commercial partnerships with ISPs and network operators
• Lookup Process:
  1. Parse and validate IP address
  2. Query geolocation database (usually binary search or tree structure)
  3. Match IP to CIDR block with location metadata
  4. Return geographic coordinates, country, region, city, ISP, ASN
• Data Structure: IP ranges stored as CIDR blocks with associated metadata
  • Example: 8.8.8.0/24 to Mountain View, CA, US (Google)
  • Hierarchical storage for efficient lookups

Accuracy and Limitations:

• Country-level: ~95-99% accurate
  • Most reliable due to RIR allocation data
  • Regulatory requirements ensure accuracy
• City-level: ~50-80% accurate within 25 miles
  • Varies by region and ISP
  • More accurate in urban areas with dense infrastructure
  • Less accurate in rural areas or when using VPN/proxy
• Coordinate-level: Approximate, not GPS-precise
  • Often represents city center or ISP location
  • NOT accurate enough for physical address
  • Legal privacy concern if misused for precise tracking
• Mobile IPs: Less accurate due to carrier-grade NAT (CGNAT)
  • Mobile carriers use centralized NAT gateways
  • IP location may show carrier hub, not user location
• VPN/Proxy/Tor: Shows VPN server location, not user location
  • Trivially bypassed for geo-fencing
  • Requires additional signals (browser fingerprint, payment method)

Geolocation Database Providers:

• MaxMind GeoIP2: Most popular commercial solution
  • City, Country, ISP, Anonymous IP databases
  • Monthly updates, downloadable databases or API
  • Free GeoLite2 version with lower accuracy
• IP2Location: Alternative commercial provider
  • 25+ data fields including weather station, ZIP code
  • More granular data in some regions
• ipinfo.io: Modern API-first service
  • JSON API with generous free tier
  • Privacy detection (VPN, proxy, Tor, hosting)
  • Company data for business IPs
• IPGeolocation.io: API service with timezone and currency data
• Abstract API: Combined IP geolocation and enrichment

Autonomous System Number (ASN):

• Definition: Unique identifier for networks participating in BGP routing
• Format: AS followed by number (e.g., AS15169 for Google)
• Allocation: Assigned by Regional Internet Registries (RIRs)
• Uses:
  • Identify ISP or hosting provider
  • Detect cloud services (AS16509 = Amazon, AS8075 = Microsoft)
  • Reputation scoring (some ASNs associated with spam/abuse)
  • DDoS mitigation (block/rate-limit by ASN)
• Example ASNs:
  • AS15169: Google LLC
  • AS13335: Cloudflare
  • AS16509: Amazon AWS
  • AS8075: Microsoft Azure
  • AS32934: Facebook/Meta

Privacy and Legal Considerations:

• Not Personal Data (usually): IP geolocation is not precise enough to identify individuals
  • GDPR: IP addresses are personal data, but geolocation may not be
  • Depends on precision and additional context
• Legitimate Interest: Common uses (localization, fraud prevention) often qualify
• User Consent: May be required depending on jurisdiction and use case
• Data Retention: Consider privacy policies and retention limits
• Transparency: Inform users if making geo-based decisions (blocking, pricing)

Use Cases in Detail:

• Fraud Detection:
  • Compare IP location to billing address and shipping address
  • Flag transactions from high-risk countries
  • Detect impossible travel (e.g., login from US then China in 5 minutes)
  • Identify VPN/proxy use during high-value transactions
• Content Localization:
  • Auto-select language based on country
  • Display regional pricing and currency
  • Show relevant products/services for market
  • Redirect to country-specific subdomain
• Geo-fencing (Regional Restrictions):
  • Enforce content licensing agreements (streaming services)
  • Comply with export control regulations
  • Regional rollouts and A/B testing
  • Limit access to specific markets
• Security:
  • Block traffic from known bad actor countries
  • Alert on logins from unusual locations
  • Investigate attack sources during incidents
  • Honeypot analysis and threat intelligence

API Integration Example (MaxMind GeoIP2):

// Install: npm install @maxmind/geoip2-node
import { Reader } from '@maxmind/geoip2-node'

const reader = await Reader.open('/path/to/GeoLite2-City.mmdb')
const response = reader.city('8.8.8.8')

console.log(response.country.isoCode) // "US"
console.log(response.city.names.en) // "Mountain View"
console.log(response.location.latitude) // 37.4056
console.log(response.location.longitude) // -122.0775

Alternative: IP API (Free Public Service):

// Free API (rate-limited, not for production)
const response = await fetch('http://ip-api.com/json/8.8.8.8')
const data = await response.json()

console.log(data.country) // "United States"
console.log(data.city) // "Mountain View"
console.log(data.isp) // "Google LLC"
console.log(data.as) // "AS15169 Google LLC"

Best Practices:

• Use geolocation as one signal among many, not sole decision factor
• Provide override mechanism (let users manually select country/language)
• Cache results to reduce API calls and latency
• Update databases monthly or use API for real-time accuracy
• Be transparent with users about geo-based decisions
• Don't assume precise location from IP (privacy and accuracy concerns)
• Test with VPN/proxy to understand evasion scenarios