In an OSPF network with routers connected together with Ethernet cabling, which topology typically takes the longest to converge?
In an OSPF network with routers connected together with Ethernet cabling, which topology typically takes the longest to converge?
In an OSPF network, a full mesh topology typically takes the longest to converge. This is because, in a full mesh topology, every router is connected to every other router. When a change occurs, each router needs to exchange information with all of its neighbors, leading to a large number of link-state advertisements (LSAs) that need to be processed and propagated. The complexity of the shortest path first (SPF) calculation increases significantly with the number of links, leading to longer convergence times.
In an OSPF network with routers connected together with Ethernet cabling, the topology that typically takes the longest to converge is the ring topology (option B). In a ring topology, there is only one path available between any two routers, and when a link fails, the OSPF routers need to recalculate the routes, which can introduce delays in the convergence process. The other options listed (squared, partial mesh, triangulated, full mesh) typically provide multiple paths between routers, which can help in faster convergence by allowing alternative routes to be used when a link fails.
Should be E "full mesh" which takes the most links ! so it will take more time on the SPF calculation !
Convergence of the ring topologies are generally slow compared to other alternatives such as partial mesh, full-mesh and diverge planes topologies. https://packetpushers.net/network-topologies/
B seems correct because in Ring topology each router first needs to exchange LSAs with its 2 direct and other neighbors and this will continue until all neighbors sync up their LSDB
Answer should be C
It should be E
Answer C: Partial mesh topologies can result in longer convergence times due to their irregular and less predictable connectivity patterns, which make it more complex for OSPF to quickly recompute optimal paths and achieve a consistent network state across all routers.
Guys It B Ring. Dont look for crappy answers
Ring has no OSPF DR/BDR election, whereas full-mesh broadcast multiaccess has DR/BDR election; not exactly sure what is the delay in DR/BDR election process besides LSA exchanges and building LSDB. Ring (SONET is a ring as well) must be OSPF point-to-point network; on a ptp network OSPF converge faster.
I vote for B as the LSA will take longer to propagate. Think of a ring of 12 routers
on top of that microloop kicks in unless LFA or RLFA is configured.Each node of the ring has to receive, process and propagate to the next router in the ring.