Exam 300-420 topic 1 question 73 discussion

The correct solution for this scenario is D. The architect should summarize the access layer networks from the aggregation layer toward the core layer to optimize the network and reduce the impact when a link fails. EIGRP is a distance-vector routing protocol that can support automatic summarization at network boundaries to reduce the size of the routing table and improve network performance. In this scenario, by summarizing the access layer networks from the aggregation layer toward the core layer, the full EIGRP routing table would be reduced in size and complexity, which would minimize the impact when a link fails.

A its the correct, by combining EIGRP with BFD, network administrators can achieve faster convergence and more reliable network connectivity. BFD enables faster detection of link failures, which triggers EIGRP to update its routing tables and choose a new best path. This reduces the amount of time it takes for the network to recover from a failure and ensures that the network is always using the most optimal path available.

"currently, users experience data loss when any one link in the network fails" Only BFD does this. Answer is A

I would go with answer D. EIGRP Access Design Recommendations When EIGRP is used as the routing protocol for a fully routed or routed access layer solution, with tuning it can achieve sub-200 ms convergence. EIGRP to the distribution layer is similar to EIGRP in the branch, but it's optimized for fast convergence using these design rules: Limit scope of queries to a single neighbor: Summarize at the distribution layer to the core as is done in the traditional Layer 2 to Layer 3 border at the distribution layer. This confines impact of an individual access link failure to the distribution pair by stopping EIGRP queries from propagating beyond the core of the network. When the distribution layer summarizes toward the core, queries are limited to one hop from the distribution switches, which optimizes EIGRP convergence. see: https://www.ciscopress.com/articles/article.asp?p=1315434&seqNum=3

should be D. Its talking about optimization and not fast convergence.

The question states "when any one link in the network fails". Not just devices connected to the access network. Because of this I am going with A, BFD, sub-second convergence and path failure detection.

BFD is used to provide sub-sec link failure detection .. summerization is the correct answer. it summerizing the multiple smaller subnets to supernet ...any failure of those smaller subnets will not impact the others.

summarization doesn't really help here. BFD should be used. so answer A should be correct.

An architect must optimize the network to reduce the impact when a link fails. Summarization has nothing to do with link failure. Latter A.

Bidirectional Forwarding Detection (BFD) protocol. BFD is a detection protocol designed to provide fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing protocols

D is the correct answer