300-445 Exam Dumps : Designing and Implementing Enterprise Network Assurance(300-445 ENNA)

TheDesigning and Implementing Enterprise Network Assurance (300-445 ENNA)framework emphasizes that the goal of internet intelligence is to enable rapid and accurate escalation to the party responsible for a service degradation. Based on the evidence of a BGP Hijack identified in the previous question, the issue is occurring entirely within the public internet ecosystem.

The most appropriate next step is toreach out to the Internet Service Provider (ISP) to report the suspected BGP hijacking incident(Option B). Since the traffic is being misdirected by an external Autonomous System (AS 10297) before it reaches the intended destination (AS 16509), the fix must occur at the routing policy level of the major transit providers. The network administrator should provide the ISP with the ThousandEyes "Share Link" or screenshots showing the path change and the unauthorized AS announcement, as this data serves as proof to accelerate the ISP's mitigation efforts, such as implementing prefix filters or contacting the offending network.

Other options are ineffective for this specific scenario:

Option A:The path visualization shows that traffic is successfully leaving the local network and reaching the public internet; the problem is many hops away from the internal routers.

Option C:Blocking trafficfromAS 10297 does not solve the problem of your traffic beingattractedto it. The hijack affects how the rest of the world (including your ISP) sees the route to your destination.

Option D:DNS is not the issue; the agent successfully resolved the hostname to the correct IP, but the BGP layer misdirected the packets at the routing level.

By identifying the issue as an external routing event, the administrator avoids wasting internal resources and directly triggers the necessary external remediation.

Establishing an accurate baseline is a cornerstone of theDesigning and Implementing Enterprise Network Assurance (300-445 ENNA)methodology. A baseline must represent the "typical" behavior of the network across its standard operating cycle to be useful for anomaly detection and capacity planning. When monitoring interface utilization on a critical link, it is vital tocapture both peak and off-peak traffic patterns(Option C).

Most enterprise networks exhibit cyclical traffic patterns, often referred to as "diurnal" cycles, where utilization spikes during business hours (peak) and drops significantly at night or on weekends (off-peak). If an engineer only collects data during the lowest volume period (Option A), the baseline will be unrealistically low, leading to "false positive" alerts when normal business traffic returns. Conversely, only capturing peak data might hide background synchronization tasks or backup windows that occur during off-hours.

By selecting a representative time period—typically one full week or a month—the engineer ensures the baseline accounts for variations such as Monday morning "logon storms," mid-week steady states, and weekend maintenance. This comprehensive view allows the assurance platform (such asCisco Catalyst CenterorThousandEyes) to calculate a standard deviation and establish dynamic thresholds. If utilization deviates from these historically representative norms, the system can trigger an alert based on a true anomaly rather than a predictable daily surge. Aligning with a financial year (Option B) is irrelevant to technical performance, and limiting the data (Option D) compromises the baseline's statistical validity.

Detailed Explanation:

This analysis requires extracting two specific browser-rendering metrics from the IT Operations Dashboard. By placing the cursor over the latest metrics data points:

Page Load time:1479.6 ms.

DOM load time: 1354.3 ms.

By subtracting the DOM time from the Page Load time ($1479.6\text{ ms} - 1354.3\text{ ms} = 125.3\text{ ms}$), the engineer identifies the duration spent rendering the page after the initial document structure was established.