In OSPFv2, which route characteristic is used to determine the best path?

OSPF (Open Shortest Path First) is a link-state routing protocol that uses the Shortest Path First (SPF) algorithm, also known as Dijkstra's algorithm, to determine the best path to a destination. The metric used in this calculation is "cost." The cost of a path is the cumulative value of the costs assigned to each outgoing interface along the path from the source to the destination. The route with the lowest total cost is considered the best path and is installed in the IP routing table. The interface cost is typically calculated based on the interface's bandwidth, with higher bandwidth links having a lower cost.

A. jitter: Jitter, the variation in packet delay, is a quality of service (QoS) metric, not a routing metric used by OSPF for path selection.

B. packet loss: Packet loss is a measure of link reliability and is not directly used by the standard OSPF algorithm to calculate the best path.

D. delay: Delay is a component of the composite metric used by other protocols like EIGRP, but it is not the metric used by OSPF.

1. Moy

J. (1998). RFC 2328: OSPF Version 2. The Internet Engineering Task Force (IETF). Section 2.2

"The Shortest-Path Tree

" states

"The cost of a path is the sum of the costs of the links in the path. The algorithm calculates the shortest-path tree

with the calculating router as the root." Available at: https://doi.org/10.17487/RFC2328

2. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. In Chapter 5

Section 5.4.2

"The Link-State (LS) Routing Algorithm

" the text explains that OSPF uses Dijkstra's algorithm where the cost of a link is the metric used for path calculation.

3. Stanford University. (n.d.). CS144: Introduction to Computer Networking - Lecture 13: Intra-domain Routing. Lecture Slides. Slide 21 discusses OSPF

explicitly stating

"Link cost configured by administrator... Router computes least cost path to all nodes." Retrieved from the Stanford CS144 course materials archive.