A network engineer is evaluating internal dynamic routing protocols to replace legacy static routing across a multi-vendor enterprise infrastructure. The design requires a protocol that maintains complete topology visibility within an area and uses link bandwidth as its primary metric metric calculation. Which of the following statements correctly describe operational characteristics of Open Shortest Path First (OSPF)? (Select TWO.)
- OSPF uses Dijkstra's Shortest Path First algorithm to construct a loop-free topology tree based on link cost metrics.Answer
- BOSPF encapsulates routing updates inside Layer 4 TCP segments using port 179 to guarantee transport delivery.
- OSPF routers maintain full topology awareness of all routers and links within their designated local area via Link-State Advertisements.Answer
- DOSPF requires Static NAT to translate internal IP routing prefixes before advertising routes to neighboring routers.
Answer
The correct statements are that OSPF uses Dijkstra's Shortest Path First algorithm to construct a loop-free topology tree based on link cost metrics, and that OSPF routers maintain full topology awareness of all routers and links within their designated local area via Link-State Advertisements.
OSPF relies on Link-State Advertisements (LSAs) to build a synchronized Link-State Database (LSDB) within an area, giving every router complete visibility into the area topology. Each router independently runs Dijkstra's Shortest Path First (SPF) algorithm on this database to determine the lowest cumulative cost path to every destination prefix.
Step-by-Step Solution
Key Concept
Link-State Dynamic Routing Protocol Mechanics (OSPF)