OSPF Design Considerations for Network Growth

Supporting Network Growth

Question

Which two OSPF design considerations should you implement to support the eventual growth of a network, so that CPU and memory are unaffected by the size and complexity of the link-state database in a large service provider network? (Choose two.)

Answers

Explanations

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A. B. C. D. E. F.

CE.

To support the eventual growth of a network and prevent the CPU and memory from being affected by the size and complexity of the link-state database in a large service provider network, the following two OSPF design considerations should be implemented:

  1. Create Network Summaries: OSPF uses the concept of network summarization to minimize the size of the routing table and reduce the amount of traffic that is sent across the network. Network summarization involves consolidating multiple IP subnets into a single, larger IP subnet, and advertising the summary address rather than individual subnets. By doing this, the size of the link-state database is reduced, which in turn reduces the amount of CPU and memory required to manage the OSPF routing tables. This approach helps to prevent scalability issues that can arise in large OSPF networks with many subnets.

  2. Turn on the Incremental SPF feature: The Incremental SPF (Shortest Path First) feature is used in OSPF networks to optimize the calculation of the shortest path to a destination when a change occurs in the network topology. Without this feature, the entire network would have to be recalculated every time a change occurs, which can be CPU and memory-intensive, and can lead to network convergence delays. By enabling incremental SPF, OSPF only calculates the shortest path to the destination that has been affected by the topology change, rather than the entire network. This approach helps to reduce the amount of CPU and memory required to manage the OSPF routing tables and improves network convergence times, which is particularly important in large service provider networks where rapid convergence times are essential.

Option A (Turn on route dampening) is not related to OSPF design considerations for supporting network growth and preventing CPU and memory issues.

Option D (Add more memory) is a general solution that can be applied to address CPU and memory issues, but it does not specifically address OSPF design considerations for network growth.

Option E (Turn on packet pacing) is a feature used to limit the rate at which packets are sent across the network, and it is not related to OSPF design considerations.

Option F (Add redundancy between critical locations) is important for ensuring high availability and resilience in a network, but it is not related to OSPF design considerations for supporting network growth and preventing CPU and memory issues.