The statement is incorrect. The calculation of routes within a single OSPF area, known as intra-area route calculation, is performed by the Shortest Path First (SPF) algorithm. This algorithm constructs a topological database of the area using only Router LSAs (Type 1) and Network LSAs (Type 2). These two LSA types provide all the necessary information about routers and network segments to build the shortest-path tree for destinations within that area.

Summary LSAs (Type 3) are not used for intra-area route calculation. Instead, they are generated by Area Border Routers (ABRs) to advertise routes from one area into another. A router uses the results of its intra-area SPF calculation to find the shortest path to the ABR, and then uses the information in the Summary LSA to learn about routes in other areas (inter-area routes). Therefore, Summary LSAs are fundamental to inter-area route calculation, not intra-area.

This is a True/False question. The statement is evaluated as False because it incorrectly includes Summary LSAs as a component of the intra-area route calculation process. The process for calculating routes strictly within an area's topology relies exclusively on Type 1 and Type 2 LSAs.

1. Huawei HCIP-Datacom-Core Technology V1.0 Training Material: In the module describing OSPF route calculation

it is detailed that the intra-area SPF algorithm computes the shortest path tree based on the topology constructed from Type-1 (Router) and Type-2 (Network) LSAs. The material explicitly separates this from inter-area route calculation

which uses Type-3 (Summary) LSAs advertised by ABRs. (Refer to Chapter: OSPF Advanced Features

Section: OSPF Route Calculation).

2. RFC 2328 - OSPF Version 2: This is the standard defining the OSPF protocol.

Section 16.1

"Calculating the shortest-path tree for an area": This section details the SPF algorithm's operation. It states

"The shortest-path tree is calculated from the area's link-state database. The database is formed from the collection of router-LSAs and network-LSAs that have originated from the area's routers." This explicitly limits the inputs for the intra-area SPF calculation to Type 1 and Type 2 LSAs.

Section 16.2

"Calculating inter-area routes": This section describes the subsequent step where Summary LSAs (Type 3) are used. It explains that inter-area paths are calculated by examining summary-LSAs

using the already-calculated intra-area distance to the advertising ABR. This confirms that Type 3 LSAs are used for a separate

inter-area calculation process.

3. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. University-level networking textbooks consistently describe the OSPF link-state algorithm. In chapters covering OSPF

the process is explained as building a complete topological map of an area using the LSAs generated by routers within that area (Type 1 and Type 2). The advertisement of summarized reachability information to other areas via ABRs (Type 3 LSAs) is treated as a distinct mechanism for inter-area routing. (Refer to Chapter 5

The Network Layer: Control Plane

Section on OSPF).