AWS Certified Advanced Networking Specialty Practice Exam

What could be the cause of packet loss for your r4.large instance if it previously handled a higher load?

1. The instance is experiencing insufficient bandwidth

2. Network credits may have been accumulated before testing

3. The instance is overloaded with too many connections

4. The Amazon Virtual Private Cloud (VPC) is misconfigured

The correct answer is: Network credits may have been accumulated before testing

The correct answer highlights that network credits may have been accumulated before testing. In AWS, particularly with certain instance types that use a burstable performance model, like T2 and T3, instances accumulate network credits during periods of low usage, which can later be used to burst to higher bandwidth when needed. If an r4.large instance was previously handling a higher load, it might have had a significant number of network credits stored. When testing occurs and the instance experiences a higher volume of traffic without properly managing these credits, the instance may not be able to maintain optimal performance, leading to packet loss. This situation elucidates the importance of understanding how AWS allocates network resources and how credits can impact performance. When credits are exhausted and bandwidth dips below a necessary threshold, packet loss can start occurring even if the instance type is capable of handling more data under normal circumstances. The other options could contribute to networking issues, but they do not explain the specific scenario of packet loss linked to a previous higher load handled by the instance as effectively as the accumulation of network credits. For instance, insufficient bandwidth may seem plausible, but if the instance was previously handling a load effectively, it's more indicative of a credit management issue. Overloading connections and misconfiguration in a VPC