LinkStateAnkündigungen

LinkStateAnkündigungen, often translated as Link State Advertisements (LSAs), are a fundamental component of link-state routing protocols, such as OSPF (Open Shortest Path First) and IS-IS. These advertisements are packets exchanged between routers within an autonomous system to inform adjacent routers about the state of their network links. Each LSA contains information about a router's directly connected networks, including the status of those links (up or down), any associated costs or metrics, and the IP addresses of connected interfaces.

Routers flood LSAs throughout the routing domain. When a router receives an LSA, it updates its own link-state database. This database serves as a complete map of the network topology. By having a consistent and up-to-date link-state database, each router can independently calculate the shortest path to all other destinations using an algorithm like Dijkstra's. This distributed knowledge of the network topology ensures efficient and loop-free routing. Different types of LSAs exist within protocols like OSPF, each carrying specific information about network elements like routers, networks, and inter-area links, contributing to a comprehensive understanding of the network's structure.