Important Cisco 300-445 ENNA Exam Questions

Answer: C

Explanation:

As shown in Exhibit 4.1-1 (image_6e19fb.png), the alert rule is configured for the BGP layer with the name 'AS origin AS 1234'. The critical logic is defined in the Alert Conditions section, which specifies: BGP Origin meets all of: ASN not in 1234.

This specific configuration is the standard method used in ThousandEyes to detect BGP hijacking (Option C). BGP hijacking occurs when an unauthorized Autonomous System (AS) announces a network prefix that it does not own, effectively stealing the traffic meant for the legitimate owner. By setting an alert that triggers when a monitored prefix is seen originating from an Autonomous System Number (ASN) that is not the expected authorized ASN (in this case, AS 1234), ThousandEyes provides immediate notification of a routing takeover.

Identifying this via BGP Origin alerts is superior to simple connectivity checks because it catches the issue at the routing control plane.

DNS Issues (Options B and D): These involve the translation of names to IPs and would be detected via DNS-specific tests rather than BGP Origin checks.

Route Poisoning (Option A): This is a generic term often referring to the manipulation of distance-vector protocol metrics to make a route unreachable; while related to routing, BGP Origin checks are the specific tool for detecting external prefix hijacks.

By monitoring the ASN origin, network engineers can quickly distinguish between a local ISP outage and a global security event where their traffic is being misdirected to an illegitimate network.

Answer: B

Explanation:

In wireless network assurance, high channel utilization and increased retransmissions are clear indicators of RF interference or over-subscription. Retransmissions are particularly damaging to voice call quality because they introduce significant jitter and late-arrival packet loss that the jitter buffer cannot overcome.

The recommended optimization is to change the access point to a different, less congested channel (Option B). This directly reduces the competition for airtime (Channel Utilization) and the likelihood of collisions from neighboring access points (Co-Channel Interference), which in turn lowers the retransmission rate. Modern wireless controllers using Radio Resource Management (RRM) often automate this, but a manual adjustment based on SNMP telemetry is a valid operational fix.

Other options are technically flawed:

Option A: Increasing transmit power often increases interference and channel utilization for surrounding cells, making the problem worse for everyone.

Option C: Disabling all non-voice traffic is an extreme measure that is rarely feasible in a real business environment.

Option D: Admission control limits the number of users but doesn't solve the underlying issue of poor channel health for those already connected.

Answer: A

Explanation:

In the Designing and Implementing Enterprise Network Assurance (300-445 ENNA) framework, managing a large-scale deployment of Endpoint Agents requires efficient categorization through Agent Labels. Agent labels are used to group agents for targeted test assignment and data filtering based on specific attributes like location, OS, or naming conventions.

ThousandEyes supports the use of wildcards (specifically the * symbol) within label filters to allow for dynamic and scalable grouping. In this scenario, the organization has adopted a naming convention of agentname-network. To capture all agents connected to the 'corporate' network regardless of the unique agentname prefix, the engineer should use the filter *-corporate (Option A) in the hostname or agent name field. The asterisk functions as a placeholder for any string of characters, ensuring that any agent ending with '-corporate' is automatically added to the label as soon as it registers with the ThousandEyes platform.

Other options are incorrect for the following reasons:

agentname-* (Option B): This would only match agents that literally start with the string 'agentname-', which is a placeholder and not a representative filter for a group of uniquely named agents.

agent*corporate (Option C): This filter is overly broad and lacks the specific hyphen delimiter used in the organization's naming convention, potentially leading to the inclusion of unintended agents.

No wildcard (Option D): Wildcards are a documented and essential feature of the ThousandEyes label system to facilitate automated management in enterprise environments.

By implementing wildcard-based labels, the network administrator ensures that new agents are seamlessly integrated into the assurance strategy without the need for manual manual intervention.

Answer: A

Explanation:

In the Designing and Implementing Enterprise Network Assurance (300-445 ENNA) architecture, a critical challenge in active synthetic monitoring is ensuring that test probes accurately reflect user traffic without being dropped by intermediate security appliances. Standard network tests often utilize separate connections for measuring performance metrics (latency/loss) and for path discovery (hop-by-hop visualization). This behavior can be flagged by stateful firewalls or Intrusion Prevention Systems (IPS) as suspicious or malicious scanning activity.

To mitigate this, the engineer should enable Path Trace Mode: In Session (Option A). When this mode is active, ThousandEyes performs path discovery using the exact same TCP session established for the performance measurement. By embedding path discovery probes within an active, established session, the traffic appears to firewalls as part of a legitimate, ongoing communication stream rather than an independent series of probes with varying TTL values that might trigger 'anti-spoofing' or 'scanning' alerts.

Reviewing the alternative options:

Protocol: TCP (Option B): While using TCP is generally more firewall-friendly than ICMP, the exhibit shows TCP is already selected. The issue is not the protocol itself, but how the path discovery probes are handled relative to the session.

Port: 5000 (Option C): Changing the port to a non-standard value like 5000 often makes traffic more likely to be scrutinized or blocked by default firewall policies compared to standard web ports like 80.

Probing Mode: Force SYN (Option D): Forcing SYN packets is a technique used to bypass certain types of load balancers but does not address the fundamental issue of path discovery probes being seen as a separate, malicious scan by stateful inspection engines.

Therefore, enabling In Session path trace mode is the most effective way to ensure consistent visibility through security-hardened environments.

Answer: B, D

Explanation:

The architecture for Designing and Implementing Enterprise Network Assurance (300-445 ENNA) specifies that ThousandEyes WAN Insights relies on deep integration with the Cisco SD-WAN management stack. To generate its predictive path recommendations, the platform must ingest specific telemetry data that reflects both the network's behavior and the applications traversing it.

The first essential data source is historical network performance metrics collected by vAnalytics (Option B). Before WAN Insights can be activated, vAnalytics must be enabled to collect and enrich raw network telemetry from the edge routers.34 This data includes granular metrics for every SD-WAN tunnel, such as packet loss, latency, and jitter.35 WAN Insights analyzes these historical trends to forecast future path quality and determine which transport circuits are most likely to meet application SLAs over a long-term period.

The second essential data source is application traffic flow data (Option D). WAN Insights must understand which applications are currently active in the fabric to prioritize recommendations for 'business-critical' services like Office 365, Webex, or custom internal apps.38 This information is ingested as flow records from the SD-WAN data plane and categorized based on the Application Lists defined in Cisco Catalyst SD-WAN Manager (vManage).

Options A and E are configuration or logging data that, while useful for general management, are not the raw telemetry inputs used by the WAN Insights predictive engine. Option C is incorrect because WAN Insights explicitly uses infrastructure telemetry rather than ThousandEyes agent-based synthetic data for its SD-WAN fabric calculations. By combining vAnalytics performance metrics and application flow data, WAN Insights can provide the 'Predictive Path Recommendatio41ns' that are a hallmark of modern network assurance.