AS (Autonomous System)

A system of multiple Network Node that has the same configuration.

In simple terms, it's basically a big network of computer or computer network that connected together that can talk to each other.

The internet is make of multiple group of Autonomous System that talk to eachother.

Each AS is asigned a number called ASN. This is like the id for that AS.

How does AS route to other AS

2 steps:

1. Routing within 1 AS to find the computer that response to broadcast outside of that AS (iBGP (Interior Border Gateway Protocol))
2. Route outside of 1 AS to another AS (eBGP (External border gateway protocol))

Use BGP (Border Gateway protocol)