ASN stands for Autonomous System Number. To understand ASNs, let’s break it down with an easy analogy.

Imagine the Internet as a giant world map, with each country having its own postal system to handle and route mail within its borders. An Autonomous System (AS) is like one of these countries. It’s a large network or group of networks that are all managed by a single organization, like a big Internet Service Provider (ISP) or a large company.

An Autonomous System Number (ASN) is like the unique identifier for each of these “countries” on the Internet. It’s a number that helps identify which autonomous system is responsible for a particular range of IP addresses.

Why Are ASNs Important?

  1. Routing Traffic: ASNs help route data across the Internet efficiently. When data travels from one network to another, it uses these numbers to figure out the best path to take.

  2. Network Management: They allow organizations to manage their network and routing policies independently.

  3. Peering and Connectivity: ASNs are crucial for setting up peering agreements between different networks, allowing them to exchange traffic directly without having to go through a third party.

Technical Explanation

An ASN is a unique number assigned by a regional Internet registry (RIR) like ARIN (American Registry for Internet Numbers) or RIPE NCC (Réseaux IP Européens Network Coordination Centre). These numbers are used in the Border Gateway Protocol (BGP), which is the protocol that makes the Internet work by routing traffic between different autonomous systems.

  • Types of ASNs: There are two types of ASNs:
    1. Public ASNs: Used for organizations that need to exchange traffic with multiple other autonomous systems on the Internet.
    2. Private ASNs: Used within an organization or between a small group of organizations. They are not used for routing traffic on the global Internet.

Example from a Big Company: Google

Google has its own ASNs because it operates a vast network of data centers and services worldwide. For example, Google’s primary ASN is 15169. This number helps route traffic efficiently across its global network, ensuring that users can access Google services quickly and reliably from anywhere in the world.

How Long Have ASNs Been Used?

ASNs have been a part of the Internet’s infrastructure since the 1980s. They were introduced as the Internet grew to help manage and route the increasing amount of data traveling between different networks. Companies like Google, Amazon, and ISPs have been using ASNs for decades to ensure smooth and efficient operation of their networks.

Top ASNs (Representative List)

A general overview of some of the top ASNs based on their significance and usage in global internet traffic. Here’s a list of some of the most prominent ASNs, which are often included in such rankings due to their extensive network operations:

  1. AS15169 - Google LLC
    • Manages Google’s vast global infrastructure.
  2. AS13335 - Cloudflare, Inc.
    • Operates Cloudflare’s global content delivery and DDoS protection network.
  3. AS8075 - Microsoft Corporation
    • Manages Microsoft’s Azure cloud services and other global network operations.
  4. AS16509 - Amazon.com, Inc.
    • Manages Amazon Web Services (AWS) infrastructure.
  5. AS32934 - Facebook, Inc.
    • Handles Facebook’s global network for its social media platforms.
  6. AS6939 - Hurricane Electric LLC
    • A major global Internet backbone provider.
  7. AS20940 - Akamai Technologies, Inc.
    • Operates Akamai’s content delivery network.
  8. AS5511 - Orange S.A.
    • A major French multinational telecommunications corporation.
  9. AS3356 - Level 3 Communications, Inc.
    • Now part of CenturyLink, provides global telecommunications services.
  10. AS7018 - AT&T Services, Inc.
    • Operates AT&T’s global telecommunications network.

How to Find Up-to-Date Information

To get the latest and most accurate list of the top 100 ASNs, you can use various online resources:

  • BGPView: Provides information on ASNs, prefixes, and peers.
  • Hurricane Electric BGP Toolkit: Offers tools to lookup ASNs and their networks.
  • RIPE NCC: The Réseaux IP Européens Network Coordination Centre provides detailed information on ASNs and their allocation.

Other Resources

These tools can help you explore and analyze ASN data in more detail.

Learn More

Here are some resources to help you understand more about ASNs: