Interior Gateway Protocols (IGPs) are a type of routing protocol used within a single autonomous system (AS) in a computer network. An autonomous system is a collection of IP networks and routers under a single administrative domain. IGPs are responsible for determining the best paths for routing data packets within the boundaries of the same AS.
IGPs help routers within the same network share information about network topology, IP addresses, and routing decisions. They ensure that routers can efficiently exchange routing information and make data forwarding decisions to ensure data reaches its intended destination within the AS.
Common IGPs are:
- RIP (Routing Information Protocol): A simple and distance-vector-based protocol used for small networks. It has limitations in scalability and convergence time.
- OSPF (Open Shortest Path First): A link-state protocol that calculates the shortest path to destination networks based on link metrics. OSPF is suitable for larger networks and offers faster convergence times compared to RIP.
- IS-IS (Intermediate System to Intermediate System): Another link-state protocol that operates similarly to OSPF and is often used in larger networks, especially in service provider environments.
IGPs operate by exchanging routing updates and maintaining routing tables to determine the best paths for forwarding traffic. They focus on the efficient use of network resources within the same autonomous system, optimizing routes based on factors such as link bandwidth, delay, and cost.
To wrap up, Interior Gateway Protocols (IGPs) are routing protocols used within a single autonomous system (AS) to exchange routing information and determine the best paths for data packet forwarding within that network. They play a critical role in optimizing communication and data transfer within a local network environment.