Full form: Link State Advertisement
Also known as: Link State Advertisement, Link-State Advertisement
Quick Definition
The information packets OSPF routers flood to share their link state with all other OSPF routers.
LSAs are the building blocks of OSPF. Each router generates LSAs describing its directly connected networks and sends them to neighbours, who forward them throughout the OSPF area. All routers in an area accumulate the same set of LSAs in their Link State Database (LSDB). The CCNA exam focuses on Type 1 (Router LSA) and Type 2 (Network LSA) within an area, and Type 3 (Summary LSA) between areas. When the LSDB is synchronised across all routers, the area has converged.
OSPF only floods LSAs within an area. Inter-area routing uses Type 3 Summary LSAs generated by ABRs (Area Border Routers). Type 5 External LSAs come from ASBRs.
LSAs are the building blocks of OSPF. Each router generates LSAs describing its directly connected networks and sends them to neighbours, who forward them throughout the OSPF area. All routers in an area accumulate the same set of LSAs in their Link State Database (LSDB). The CCNA exam focuses on Type 1 (Router LSA) and Type 2 (Network LSA) within an area, and Type 3 (Summary LSA) between areas. When the LSDB is synchronised across all routers, the area has converged.
OSPF only floods LSAs within an area. Inter-area routing uses Type 3 Summary LSAs generated by ABRs (Area Border Routers). Type 5 External LSAs come from ASBRs.
LSA falls under the Routing domain of the 200-301 exam. Understanding it in context with related terms like ospf and dr is essential for answering scenario-based questions correctly.