Cisco Certified Network Associate (CCNA) Practice Exam

Which LSA is sent by the Designated Router (DR) in a multi-access network?

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 2 - Network LSA

In a multi-access network, such as an Ethernet segment, the Designated Router (DR) plays a crucial role in optimizing the process of exchanging routing information. The correct answer is the Type 2 - Network LSA. This LSA is specifically generated and sent by the DR to provide information about the multi-access network and the routers attached to it. The Type 2 LSA contains details about the segment, such as the list of routers that are connected to the network, helping to reduce the size of the OSPF database and minimizing the amount of routing information that needs to be exchanged. This is especially important in larger networks, where each router independently advertising its own LSA would result in excessive routing overhead and inefficiencies. In contrast, other types of LSAs serve different purposes. For instance, the Type 1 - Router LSA is sent by each router to describe its own links and is used primarily in a point-to-point or point-to-multipoint setup. The Type 3 - Summary LSA is generated by Area Border Routers (ABRs) to advertise inter-area routes and does not convey information specific to a single network segment. Lastly, the Type 4 - ASBR Summary LSA is utilized for communicating routes