Which two statements about single-area and multiarea OSPF are true? (Choose two.)

IT Exam Items Repository › Category: CCNP ENCOR v9 › Which two statements about single-area and multiarea OSPF are true? (Choose two.)

Which two statements about single-area and multiarea OSPF are true? (Choose two.)

Multiarea OSPF can be used to limit the propagation and processing of LSAs.
In single-area OSPF, all routers inject routing information into the backbone router, and in turn the backbone router sends that information to other routers.
Multiarea OSPF is more scalable than single-area OSPF and is easier to implement.
In multiarea OSPF, Area 1 must be physically connected to the backbone, and all other areas must be connected to Area 1.
Single-area OSPF has one advantage over multiarea OSPF: smaller routing tables.
When a multiarea design is used, one of the areas should be Area 0.

Explanation: OSPF uses a two-layer hierarchical design to enhance scalability and efficiency. The two true statements are supported as follows:

LSA Limitation: One of the primary advantages of multiarea OSPF is that it segments the network to limit the propagation of LSAs inside a specific area. This ensures that any topology change in one area causes LSA flooding and SPF recalculations only within that specific area, rather than across the entire OSPF domain.
Requirement for Area 0: The sources explicitly state that when multiple areas are involved, OSPF has special restrictions requiring that one of the areas must be Area 0, also known as the backbone. All other non-backbone areas must connect directly to this backbone area to facilitate the distribution of routing information between them.