After studying this chapter you will be able to: Describe the basic features & concepts of link-state routing protocols, list the benefits and requirements of link-state routing protocols. | Link-State Routing Protocols Routing Protocols and Concepts – Chapter 10 Objectives Describe the basic features & concepts of link-state routing protocols. List the benefits and requirements of link-state routing protocols. Introduction Link-State Routing Link state routing protocols Also known as shortest path first algorithms These protocols built around Dijkstra’s SPF Link-State Routing Dikjstra’s algorithm also known as the shortest path first (SPF) algorithm Link-State Routing The shortest path to a destination is not necessarily the path with the least number of hops Link-State Routing Link-State Routing Process How routers using Link State Routing Protocols reach convergence Each routers learns about its own directly connected networks Link state routers exchange hello packet to “meet” other directly Connected link state routers Each router builds its own Link State Packet (LSP) which includes information about neighbors such as neighbor ID, link type, & bandwidth After the LSP | Link-State Routing Protocols Routing Protocols and Concepts – Chapter 10 Objectives Describe the basic features & concepts of link-state routing protocols. List the benefits and requirements of link-state routing protocols. Introduction Link-State Routing Link state routing protocols Also known as shortest path first algorithms These protocols built around Dijkstra’s SPF Link-State Routing Dikjstra’s algorithm also known as the shortest path first (SPF) algorithm Link-State Routing The shortest path to a destination is not necessarily the path with the least number of hops Link-State Routing Link-State Routing Process How routers using Link State Routing Protocols reach convergence Each routers learns about its own directly connected networks Link state routers exchange hello packet to “meet” other directly Connected link state routers Each router builds its own Link State Packet (LSP) which includes information about neighbors such as neighbor ID, link type, & bandwidth After the LSP is created the router floods it to all neighbors who then store the information and then forward it until all routers have the same information Once all the routers have received all the LSPs, the routers then construct a topological map of the network which is used to determine the best routes to a destination Link-State Routing Directly Connected Networks Link This is an interface on a router Link state This is the information about the state of the links Link-State Routing Sending Hello Packets to Neighbors Link state routing protocols use a hello protocol Purpose of a hello protocol: To discover neighbors (that use the same link state routing protocol) on its link Link-State Routing Sending Hello Packets to Neighbors Connected interfaces that are using the same link state routing protocols will exchange hello packets Once routers learn it has neighbors they form an adjacency 2 adjacent neighbors will exchange hello packets These packets will serve as a keep alive function .
