Understanding Autonomous Systems (AS) and AS Numbers

Introduction: The City-States of the Web

The internet isn't one single organization. It is a collection of thousands of independent 'mini-internets' called Autonomous Systems (AS). Large companies like Facebook, ISPs like AT&T, and universities like MIT all run their own AS. They make their own rules and manage their own internal IP addresses.

The AS Number (ASN)

Every AS has a unique serial number called an **ASN**. When your data travels across the world, it 'Hops' from one ASN to another. You can think of an ASN as the 'Country' code for a part of the internet.

Conclusion

By grouping billions of devices into thousands of Autonomous Systems, the internet becomes manageable and resilient. See which ASN you are in here.