An Autonomous System (AS) is a collection of IP networks and routers under the control of a single entity, such as a country, an internet service provider (ISP), or a large organization.
The routing table within a router serves as its roadmap, storing paths to different networks and guiding data packets efficiently to their destinations.
This routing is facilitated by routing protocols, which are sets of rules and procedures that routers use to communicate and exchange routing information. These protocols help routers determine the best paths for forwarding data packets across a network.
Routing protocols can be categorized into internal and external routing protocols. Internal routing protocols, like Routing Information Protocol (RIP) and Open Shortest Path First (OSPF), are used within a single autonomous system (AS) to exchange routing information among routers.
On the other hand, external routing protocols, such as Border Gateway Protocol (BGP) and Exterior Gateway Protocol (EGP), are employed between different autonomous systems to exchange routing information.
Border Gateway Protocol (BGP) is a routing protocol specifically designed to enable communication between autonomous systems (AS) on the internet
Summary:
- An Autonomous System (AS) encompasses IP networks and routers controlled by a single entity like an ISP
- routing tables guiding data packets efficiently through routing protocols like RIP and BGP, which facilitate communication within and between ASes.