What is the difference between interior and exterior routing protocols?

Interior routing protocols are used within a single autonomous system (AS) or network, while exterior routing protocols are used to exchange routing information between different autonomous systems.

Interior routing protocols, such as OSPF (Open Shortest Path First) or EIGRP (Enhanced Interior Gateway Routing Protocol), are designed to facilitate communication and routing decisions within a single network. They focus on finding the best paths within the network, considering factors like link cost, bandwidth, and network congestion. These protocols are typically used within an organization's internal network infrastructure.

On the other hand, exterior routing protocols, such as BGP (Border Gateway Protocol), are used to exchange routing information between different autonomous systems. Autonomous systems are networks that are under a single administrative control. Exterior routing protocols are responsible for determining the best path for data to travel between autonomous systems, considering factors like AS path length, network policies, and traffic load. BGP is commonly used by Internet Service Providers (ISPs) to exchange routing information between their networks.

In summary, the main difference between interior and exterior routing protocols lies in their scope and purpose. Interior routing protocols are used within a single network to facilitate communication and routing decisions, while exterior routing protocols are used to exchange routing information between different autonomous systems.