What Is My IP Address?
High-precision client-side network telemetry: Public IPv4, IPv6, ISP, ASN, and geo-routing diagnostics.
Public IP Address is the globally routable numerical identifier assigned to your connection gateway by your Internet Service Provider. It distinguishes your local network across the public internet. IPv4 addresses are 32-bit (e.g. 203.0.113.195); IPv6 addresses are 128-bit hexadecimal strings (e.g. 2606:4700:4700::1111) providing direct end-to-end global addressing.
Internet Protocol Addressing & Global Routing Architecture
Every packet routed across the internet relies on numerical addressing governed by the Internet Protocol (IP). Whether you are diagnosing WAN latency, configuring firewall access control lists (ACLs), or securing cloud ingress, understanding IP fundamentals is critical.
IPv4 vs. IPv6 Architecture Comparison
| Specification | IPv4 (RFC 791) | IPv6 (RFC 8200) |
|---|---|---|
| Address Length | 32 bits (4 bytes) | 128 bits (16 bytes) |
| Address Space | 232 ≈ 4.29 × 109 addresses | 2128 ≈ 3.4 × 1038 addresses |
| Notation | Dotted decimal (e.g. 198.51.100.42) |
Hexadecimal with colons (e.g. 2001:0db8::8a2e:0370:7334) |
| Header Size | 20–60 bytes (variable with options) | 40 bytes (fixed base header) |
| NAT Requirement | Standard requirement due to address exhaustion | Not required; direct end-to-end addressing |
| Configuration | Manual or DHCP | Stateless Address Autoconfiguration (SLAAC) or DHCPv6 |
Public vs. Private IP Addresses (RFC 1918 & Carrier-Grade NAT)
Local area networks use non-routable private address blocks reserved by the Internet Assigned Numbers Authority (IANA). These addresses cannot exist directly on the public internet:
- Class A Range:
10.0.0.0/8(10.0.0.0 to 10.255.255.255) — Enterprise networks and large data centers. - Class B Range:
172.16.0.0/12(172.16.0.0 to 172.31.255.255) — Medium-to-large business infrastructure. - Class C Range:
192.168.0.0/16(192.168.0.0 to 192.168.255.255) — Standard home Wi-Fi routers and small offices. - Carrier-Grade NAT (CGNAT, RFC 6598):
100.64.0.0/10— Used by telecom carriers to share a single public IPv4 pool across hundreds of mobile subscribers.
Understanding Autonomous System Numbers (ASN) & BGP Routing
The internet is not a single monolith, but a global confederation of over 100,000 independent networks called Autonomous Systems (AS). Each Autonomous System is assigned an ASN by regional registries (ARIN, RIPE, APNIC, LACNIC, AFRINIC) and exchanges routing tables using the Border Gateway Protocol (BGP). The ISP shown in your diagnostic card corresponds to the primary ASN announcing your IP block to Tier-1 transit backbones.
Frequently Asked Questions
What is the difference between my public IP and local IP?
Your local IP (e.g. 192.168.1.15) is assigned by your local Wi-Fi router and is only visible inside your home or office. Your public IP is assigned by your ISP and is the outward-facing identity seen by all external web servers, gaming nodes, and APIs.
Can an IP address expose my exact physical street address?
No. IP geolocation relies on BGP routing announcements and ISP registration data. It resolves to your ISP's regional point of presence (POP), city, or exchange center — typically accurate within a few miles, but never revealing your exact house or apartment number.
Why does my public IP change periodically?
Most consumer broadband and cellular subscriptions use dynamic IP allocation via DHCP. ISPs cycle addresses periodically to maximize IPv4 pool efficiency. If you require a permanent unchanging IP for hosting services, you must purchase a static IP reservation from your carrier.
How does a VPN mask my IP address?
A Virtual Private Network (VPN) encrypts your traffic and routes it through an intermediary server. Websites you visit see the VPN datacenter's public IP rather than your residential ISP gateway, concealing your physical location and internet service provider.