Cisco Certified Network Associate (CCNA) Practice Exam

What type of LSA does each router in the area send to announce its presence?

1. Type 1 - Router LSA

2. Type 2 - Network LSA

3. Type 3 - Summary LSA

4. Type 4 - ASBR Summary LSA

The correct answer is: Type 1 - Router LSA

The correct answer is indeed the type 1 - Router LSA. In OSPF (Open Shortest Path First), when a router comes online, it generates a Router LSA to announce its presence to other routers in the same OSPF area. This LSA contains information about the router’s interfaces and their status, which helps neighboring routers to understand the topology of the network, including which routers are present and how they are interconnected. Type 1 LSAs are crucial for maintaining the link-state database, and they play a fundamental role in the OSPF routing process, ensuring that all routers in the area have a consistent view of the network. The other types of LSAs serve different purposes within the OSPF framework. For example, Type 2 LSAs are used to describe multi-access networks, Type 3 LSAs summarize routes between OSPF areas, and Type 4 LSAs relay information from an Autonomous System Boundary Router (ASBR) to other areas.