What is BGP and How Internet Routing Works

Border Gateway Protocol (BGP) is the backbone of the internet. It is responsible for routing traffic between different networks, known as Autonomous Systems (AS).

What is an Autonomous System?

An Autonomous System is a network managed by a single organization, such as an ISP or a large company. Each AS has a unique number called ASN.

How BGP Works

BGP exchanges routing information between AS networks. It determines the best path for data based on policies, AS paths, and attributes.

Key BGP Concepts

• AS Path: Sequence of AS numbers a route passes through
• Next Hop: Next router in the path
• Local Preference: Preferred route inside an AS

Why BGP is Important

Without BGP, the internet would not function. It ensures that data can travel across different networks globally.

BGP Issues

• Route leaks
• Misconfigurations
• Routing loops

Conclusion

BGP is a complex but essential protocol that powers the global internet infrastructure.