Which OSPF Type LSA is known as the Network LSA?

The correct identification of the OSPF Type LSA known as the Network LSA is Type 2. In OSPF (Open Shortest Path First), different types of LSAs (Link State Advertisements) serve various purposes in the exchange of routing information.

Type 2 LSAs, or Network LSAs, are generated by the designated router (DR) of a broadcast or non-broadcast multiple access (NBMA) network segment. This LSA represents all the routers on that particular network segment, essentially summarizing the connectivity of the routers to the DR. Thus, it provides a comprehensive view of the network topology within that segment.

In the context of OSPF, different LSA types have specific roles:

• Type 1 LSAs represent the router links and are generated by all OSPF routers.

• Type 3 LSAs are used to describe inter-area routes, summarizing routes from other areas.

• Type 4 LSAs identify routers that are responsible for external routes, primarily used when redistributing routes from another routing protocol into OSPF.

Understanding these distinctions allows network engineers to configure and troubleshoot OSPF deployments more effectively by recognizing how different LSAs impact the overall routing information exchanged within an OSP