---
title: "ASN"
url: https://proxy.wiki/glossary/asn/
type: Glossary Term
author: "proxy.wiki editorial"
published: 2026-08-19
updated: 2026-08-19
site: proxy.wiki
topics: ["Proxy fundamentals"]
license: CC BY 4.0 — quote freely with attribution to https://proxy.wiki/
---

# ASN

> Autonomous System Number — the identifier of the network that owns an IP range, and a primary classification signal.

**An Autonomous System Number identifies a network that controls a block of IP addresses and announces routes for it.** Every public address belongs to an autonomous system, and that ownership is public information.

## Why it decides how you are treated

Classification of an address usually starts with its ASN. An address announced by a residential broadband operator is treated as consumer traffic; one announced by a cloud platform is treated as infrastructure. This single lookup is what separates [residential](/glossary/residential-proxy/) from [datacenter](/glossary/datacenter-proxy/) in practice — not the physical location of the hardware.

## What ASN targeting gives you

Some providers let you select exits by ASN rather than only by country. That is useful when a target behaves differently per carrier, when you need to reproduce a specific network’s view of a service, or when one operator in a country performs noticeably better than the rest.

## Checking an address

Any IP lookup service reports the ASN, usually formatted as `AS3320` followed by the operator name. It is the first thing to check when a supposedly residential address behaves as though it were flagged.