# IP Trackers > Free IP address lookup and network diagnostics. Tools for IPv4/IPv6 detection, ASN and ISP lookup, DNS and WHOIS, VPN leak testing (DNS, WebRTC, IPv6), proxy detection, and IP blacklist checking. Plain-language explainers on networking, privacy, CGNAT, and VPN topics. ## Tools - [What Is My IP Address](https://www.ip-trackers.com/): Public IPv4 and IPv6 detection with ISP, ASN, geolocation, and timezone context. - [IP Location Lookup](https://www.ip-trackers.com/ip-location): Look up the approximate location, ISP, and ASN of any IP address. - [Is My VPN Working](https://www.ip-trackers.com/is-my-vpn-working): End-to-end VPN verification: IP change, DNS leaks, WebRTC exposure, and IPv6 reachability in one workflow. - [DNS Leak Test Guide](https://www.ip-trackers.com/dns-leak-test): Walkthrough on testing whether DNS queries leak outside the VPN tunnel; routes to the active verification tools. - [WebRTC Leak Test](https://www.ip-trackers.com/webrtc-leak-test): Check whether the browser is exposing local or public IPs through WebRTC. - [IPv6 Leak Test](https://www.ip-trackers.com/ipv6-leak-test): Verify that IPv6 traffic is not bypassing the VPN tunnel. - [Proxy and VPN Detection](https://www.ip-trackers.com/proxy-check): Check whether an IP is flagged as a proxy, VPN exit, or hosting provider. - [ASN Lookup](https://www.ip-trackers.com/asn-lookup): Identify the autonomous system, network owner, and routing context behind any IP. - [WHOIS / RDAP Lookup](https://www.ip-trackers.com/whois-lookup): Registration, allocation, and abuse contact data for IP blocks and domains. - [DNS Lookup](https://www.ip-trackers.com/dns-lookup): Resolve A, AAAA, MX, TXT, NS, and CNAME records. - [Reverse DNS Lookup](https://www.ip-trackers.com/reverse-dns): Query PTR records and see the hostname assigned to an IP. - [Hostname to IP](https://www.ip-trackers.com/hostname-to-ip): Forward DNS resolution from hostname to IPv4 or IPv6. - [IP Blacklist Check](https://www.ip-trackers.com/ip-blacklist-check): Test whether an IP is listed on common DNSBL spam and abuse lists. - [MAC Address Lookup](https://www.ip-trackers.com/mac-address-lookup): OUI vendor lookup for MAC addresses. ## Directories - [ASN Directory](https://www.ip-trackers.com/asn): Major autonomous systems with prefix counts and operator details. - [ISP Directory](https://www.ip-trackers.com/isp): ISP profiles with city-level coverage and ASN context. - [VPN Directory](https://www.ip-trackers.com/vpn): VPN providers with feature, pricing, and audit context. - [Top VPNs](https://www.ip-trackers.com/top-vpn): Curated VPN picks by use case (streaming, privacy, free). - [Free VPNs](https://www.ip-trackers.com/free-vpns): Safer free VPN options with caveats and audited claims. - [Best VPS Hosting](https://www.ip-trackers.com/best-vps-hosting): VPS provider comparison. - [Best Cheap Hosting](https://www.ip-trackers.com/best-cheap-hosting): Budget hosting picks. - [Best WordPress Hosting](https://www.ip-trackers.com/best-wordpress-hosting): WordPress-optimized hosting. ## Data downloads (free, CC BY 4.0 with attribution) - [ASN Directory JSON](https://www.ip-trackers.com/api/asn-directory): Full ASN directory as JSON with metadata (asn, name, category, region, summary). CORS-open. Permitted to use with attribution back to ip-trackers.com. - [ASN Directory CSV](https://www.ip-trackers.com/api/asn-directory/csv): Same data as a downloadable CSV. Columns: asn, name, category, region, summary. ## Citable facts - CGNAT range is 100.64.0.0/10 (RFC 6598 shared address space). Source: https://www.ip-trackers.com/blog/cgnat-ip-address-range - TunnelBear 5th annual Cure53 independent security audit duration: 47 days. 6th annual: 42 days. Source: https://www.ip-trackers.com/blog/tunnelbear-review - Proton VPN free tier in 2026 has six limitations: 5 countries only, 1 device at a time, no P2P, no streaming-optimised servers, no Secure Core, no NetShield/port forwarding. Bandwidth is unlimited. Source: https://www.ip-trackers.com/blog/protonvpn-review - Windscribe free plan monthly data limit in 2026: 10 GB after email confirmation (2 GB without). 10 countries, unlimited connections, R.O.B.E.R.T. ad/tracker blocker. Source: https://www.ip-trackers.com/blog/windscribe-review - To disable WebRTC in Firefox: set media.peerconnection.enabled to false in about:config. Source: https://www.ip-trackers.com/webrtc-leak-test - Safari 12 and later block WebRTC IP enumeration by default. Source: https://www.ip-trackers.com/webrtc-leak-test ## Reference articles ### IP and networking fundamentals - [What Is My IP Address](https://www.ip-trackers.com/blog/what-is-my-ip): How public IP addresses work and what they reveal. - [Public vs Private IP](https://www.ip-trackers.com/blog/public-vs-private-ip): The difference and why both exist. - [IPv4 vs IPv6](https://www.ip-trackers.com/blog/ipv4-vs-ipv6): Address space, syntax, and why IPv6 deployment matters. - [Reserved IP Address Blocks](https://www.ip-trackers.com/blog/reserved-ip-address-blocks): RFC 1918, RFC 6598, loopback, and other reserved ranges. - [CIDR Explained](https://www.ip-trackers.com/blog/cidr-explained): Reading CIDR notation and subnet sizing. - [What Is an ASN](https://www.ip-trackers.com/blog/what-is-asn): Autonomous system numbers and BGP routing context. - [What Is My ISP](https://www.ip-trackers.com/blog/what-is-my-isp): How to identify your internet provider and verify ASN context. ### CGNAT and connectivity - [CGNAT IP Address Range](https://www.ip-trackers.com/blog/cgnat-ip-address-range): The CGNAT range is 100.64.0.0/10 (RFC 6598). How to confirm CGNAT, why port forwarding fails, and realistic fixes. - [Port Forwarding Not Working with CGNAT](https://www.ip-trackers.com/blog/port-forwarding-not-working-cgnat): Why CGNAT prevents inbound connections and how to work around it. ### DNS and PTR - [Understanding DNS](https://www.ip-trackers.com/blog/understanding-dns): How DNS resolution works end to end. - [Reverse DNS Lookup](https://www.ip-trackers.com/blog/reverse-dns-lookup): What PTR records mean and how to read them. - [PTR Record Explained](https://www.ip-trackers.com/blog/ptr-record-explained): PTR record structure, FCrDNS, and use cases. - [What Is Whois](https://www.ip-trackers.com/blog/what-is-whois): WHOIS and RDAP data sources and what they show. - [What Is DNSBL](https://www.ip-trackers.com/blog/what-is-dnsbl): How DNS blacklists work and how listings happen. ### VPN and privacy - [What Is a VPN](https://www.ip-trackers.com/blog/what-is-vpn): Practical VPN explainer. - [Proxy vs VPN](https://www.ip-trackers.com/blog/proxy-vs-vpn): When each is the right tool. - [How to Hide My IP](https://www.ip-trackers.com/blog/how-to-hide-my-ip): VPN, Tor, proxies, and their tradeoffs. - [How to Fix a VPN DNS Leak](https://www.ip-trackers.com/blog/dns-leak-test-vpn): Step-by-step DNS leak fix for Windows, Mac, and Chrome/Firefox. Covers VPN client toggle, browser DoH overrides, IPv6 leak blocking, and DNS cache flushing. - [VPN Connected but IP Not Changing](https://www.ip-trackers.com/blog/vpn-connected-ip-not-changing): Common reasons and fixes. - [Why Is My IP Location Wrong](https://www.ip-trackers.com/blog/why-is-my-ip-location-wrong): Why geolocation can be inaccurate. ### VPN reviews - [Proton VPN Review](https://www.ip-trackers.com/blog/protonvpn-review): Free tier limitations (5 countries, 1 device, no P2P, no Secure Core), Swiss jurisdiction, open-source apps. - [Mullvad Review](https://www.ip-trackers.com/blog/mullvad-review): Anonymous accounts and flat EUR 5 pricing. - [Windscribe Review](https://www.ip-trackers.com/blog/windscribe-review): 10 GB monthly free plan data limit (after email confirmation), R.O.B.E.R.T. DNS blocking, Build-a-Plan pricing. - [TunnelBear Review](https://www.ip-trackers.com/blog/tunnelbear-review): Cure53 audit duration (5th annual 47 days, 6th 42 days), free 2 GB tier, McAfee ownership. - [NordVPN Review](https://www.ip-trackers.com/blog/nordvpn-review): Server count, streaming, and security features. - [ExpressVPN Review](https://www.ip-trackers.com/blog/expressvpn-review): Streaming, Lightway, and pricing. - [Surfshark Review](https://www.ip-trackers.com/blog/surfshark-review): Unlimited devices and Nexus. - [Proton VPN vs Mullvad](https://www.ip-trackers.com/blog/protonvpn-vs-mullvad): Privacy, price, streaming, and feature comparison. - [NordVPN vs ExpressVPN](https://www.ip-trackers.com/blog/nordvpn-vs-expressvpn): Direct comparison. - [Surfshark vs NordVPN](https://www.ip-trackers.com/blog/surfshark-vs-nordvpn): Direct comparison. ### AI and modern threats - [Can AI Find My Location](https://www.ip-trackers.com/blog/can-ai-find-my-location): What AI chat tools see about location and where real leaks happen. - [How AI Is Changing VPN Detection](https://www.ip-trackers.com/blog/ai-changing-vpn-detection): Machine-learning VPN detection and residential proxy battlegrounds. - [AI Company IP Ranges](https://www.ip-trackers.com/blog/ai-company-ip-ranges): Identifying traffic from major AI providers. - [Block AI Scrapers](https://www.ip-trackers.com/blog/block-ai-scrapers): Practical tactics for limiting AI crawler access. ## About - [About IP Trackers](https://www.ip-trackers.com/about): Site mission and scope. - [Methodology](https://www.ip-trackers.com/methodology): How tools, data, and rankings are produced. - [Editorial Policy](https://www.ip-trackers.com/editorial-policy): Sourcing, review, and update standards. - [Privacy Policy](https://www.ip-trackers.com/privacy): Data handling and cookie practices. - [Author: Tudor Uzun](https://www.ip-trackers.com/authors/pro/theodore-uzun): Site author and reviewer profile. - [Glossary](https://www.ip-trackers.com/glossary): IP, DNS, and networking terminology. ## Optional - [Sitemap (XML)](https://www.ip-trackers.com/sitemap.xml): Full URL inventory for crawlers. - [RSS Feed](https://www.ip-trackers.com/rss.xml): Latest articles. - [Blog Index](https://www.ip-trackers.com/blog): All published guides and reviews. - [FAQ](https://www.ip-trackers.com/faq): Common questions about the tools and data.