A network engineer is analyzing the convergence behavior of a core enterprise router running Open Shortest Path First (OSPF). An active link on an adjacent network interface suddenly fails, triggering a topology update across the area. Place the operational steps in the correct sequential order from initial failure detection to final packet forwarding updates.
- 1The local router detects the link status change and generates a new Link-State Advertisement (LSA) reflecting the altered interface state.
- 2The local router floods the LSA out all active OSPF-enabled interfaces to inform neighboring routers across the area.
- 3Receiving OSPF routers update their local Link-State Database (LSDB) with the new topology information.
- 4Each router executes Dijkstra's Shortest Path First (SPF) algorithm against the synchronized LSDB to construct a new shortest-path tree.
- 5The router updates its IP routing table (RIB) with the newly calculated optimal next-hop routes to reach affected subnets.
Cevap
The correct sequence for OSPF link-state convergence is: 1) Generate LSA upon failure detection, 2) Flood LSA to neighbors, 3) Update local LSDB with new information, 4) Run SPF algorithm on updated LSDB, and 5) Populate the IP routing table with recalculated optimal paths.
OSPF is a link-state routing protocol operating in distinct sequential phases during topology changes. When a link fails, the detecting router immediately originates a new Link-State Advertisement (LSA). This LSA is flooded out active interfaces to ensure area-wide synchronization. Upon receiving the LSA, neighboring routers insert it into their Link-State Database (LSDB). Once the LSDB reflects the true network state, each router executes Dijkstra's Shortest Path First (SPF) algorithm to calculate the new shortest path tree. Finally, the newly derived best paths are installed into the router's IP routing table for packet forwarding.
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OSPF Link-State Convergence and SPF Calculation Sequence
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