What Is My ISP — Identify Carrier, Autonomous System & Organization
The What Is My ISP tool is a carrier detection utility that analyzes your outbound IP address to identify your Internet Service Provider, network organization, Autonomous System Number (ASN), and carrier routing hub. It determines whether your connection is a residential broadband line, mobile cellular provider, or hosting datacenter.
Carrier Telemetry & ASN Inspector
Querying regional registry BGP routing tables for ASN, carrier identity, and network categorization.
Querying reverse DNS maps for carrier routing headers...
Autonomous System Numbers (ASN) & BGP Core Routing
Global internet connectivity is organized into thousands of independent network domains called Autonomous Systems (AS). Each Internet Service Provider operates one or more ASNs governed by Border Gateway Protocol (BGP) routing tables:
Citable Major Carrier ASN Registry Examples:
- Comcast Xfinity:
AS7922(Comcast Cable Communications, LLC) - AT&T Internet:
AS7018(AT&T Services, Inc.) - Verizon Fios:
AS701(MCI Communications Services LLC) - Charter Spectrum:
AS20115(Charter Communications Inc) - Cloudflare Edge:
AS13335(Cloudflare, Inc.)
Carrier Verification Logic: When you connect to our endpoint, the server inspects the source IPv4/IPv6 packet header, checks the Regional Internet Registry (RIR) database (ARIN, RIPE, APNIC, LACNIC, AFRINIC), and extracts the registered Autonomous System entity.
Practical Diagnostic Applications
1. Verifying ISP Outages & Tech Support
When calling customer support or inspecting DownDetector reports, having your exact Autonomous System Number and registered carrier hub avoids misdiagnosing local line issues with broader upstream peering failures.
2. Detecting VPN Leaks & Corporate Proxies
If you are connected to a privacy VPN client and this tool still displays your residential telecom carrier (e.g. Spectrum or AT&T), your VPN has a routing leak and is exposing your true traffic origin.
How to Interpret the Carrier Telemetry Output
Frequently Asked Questions
How does the What Is My ISP tool identify my provider?
The tool queries Regional Internet Registries (such as ARIN and RIPE) to cross-reference your public IP address against allocated CIDR network blocks registered by telecommunication carriers.
Why does the detected ISP show a different company than who I pay my bill to?
Many regional broadband providers, local fiber cooperatives, and virtual network operators (MVNOs) lease wholesale transit capacity from national Tier-1 carriers, whose names appear on the BGP routing registry.
Can my Internet Service Provider see which specific websites I visit?
While HTTPS encrypts individual page contents, unencrypted DNS lookups and Server Name Indication (SNI) packet headers still reveal target domain names to your ISP unless you utilize DNS-over-HTTPS (DoH) or a VPN.