AWS Certified Advanced Networking - Specialty ANS-C01 Practice Test 59
Question 580
An AWS network architect encounters this situation: An HPC application needs low-latency communication among tightly coupled EC2 nodes. Which change BEST meets the documented requirement?
- Evaluate Global Accelerator endpoints for an appropriate supported workload
- Review Transit Gateway multicast capabilities and appropriate instance or attachment constraints
- Cache eligible objects at CloudFront edge locations to reduce repeated regional egress
- Use supported Elastic Fabric Adapter-enabled instances in an appropriate placement design
Explanation
Correct Answer
D:Use supported Elastic Fabric Adapter-enabled instances in an appropriate placement design. The stated configuration and business requirement call for this change because eFA offers specialized low-latency networking for eligible HPC workloads. Leaving the existing gap unresolved could mean that an ordinary ENI is not automatically equivalent to an EFA for HPC communication. Confirm the improvement by showing that measured inter-node latency and application scaling improve on supported hosts.
Incorrect Answers
A:Evaluate Global Accelerator endpoints for an appropriate supported workload would address a different scenario, such as when a global HTTP API has regional users with highly variable internet route quality and cannot tolerate long path detours. The present issue requires use supported Elastic Fabric Adapter-enabled instances in an appropriate placement design because the network path and control point are different; the alternative does not directly meet this requirement.
B:Review Transit Gateway multicast capabilities and appropriate instance or attachment constraints would address a different scenario, such as when a company wants to receive multicast from on premises into AWS applications but its current peering design lacks required support. The present issue requires use supported Elastic Fabric Adapter-enabled instances in an appropriate placement design because the network path and control point are different; the alternative does not directly meet this requirement.
C:Cache eligible objects at CloudFront edge locations to reduce repeated regional egress would address a different scenario, such as when a company transfers the same static downloads repeatedly between remote users and one AWS Region. The present issue requires use supported Elastic Fabric Adapter-enabled instances in an appropriate placement design because the network path and control point are different; the alternative does not directly meet this requirement.
Question 581
An engineer selects the change "Correct the customer route filter to accept and advertise the intended network prefixes" because One Site-to-Site VPN tunnel is healthy but a peer refuses incoming routes because of a prefix filter. Which technical explanation BEST supports it?
- Tunnel establishment and routing prefix acceptance are distinct steps in working connectivity
- Physical failure-domain diversity matters more than the number of BGP sessions on one circuit
- Transit Gateway Connect combines the supported GRE overlay with BGP route exchange
- Public VIF reachability has its own route advertisement requirements separate from VPC private routing
Explanation
Correct Answer
A:Tunnel establishment and routing prefix acceptance are distinct steps in working connectivity. This mechanism directly explains why the proposed change, correct the customer route filter to accept and advertise the intended network prefixes, fits this particular packet path or control requirement. Without it, an IPsec-up tunnel does not guarantee the required subnet route is installed. A suitable verification is that customer and AWS route tables contain the authorized destination prefixes.
Incorrect Answers
B:Physical failure-domain diversity matters more than the number of BGP sessions on one circuit explains a different case, for example when a company wants a redundant connection but its two hosted Direct Connect links terminate in the same colocation facility. In the current topology, the deciding factor is that tunnel establishment and routing prefix acceptance are distinct steps in working connectivity; this choice therefore does not explain the specified remedy.
C:Transit Gateway Connect combines the supported GRE overlay with BGP route exchange explains a different case, for example when a company uses a Transit Gateway Connect attachment to carry SD-WAN routes but the overlay peer is not Established. In the current topology, the deciding factor is that tunnel establishment and routing prefix acceptance are distinct steps in working connectivity; this choice therefore does not explain the specified remedy.
D:Public VIF reachability has its own route advertisement requirements separate from VPC private routing explains a different case, for example when a company needs public AWS service API access across a Direct Connect public VIF but has not advertised eligible public prefixes. In the current topology, the deciding factor is that tunnel establishment and routing prefix acceptance are distinct steps in working connectivity; this choice therefore does not explain the specified remedy.
Question 582
For the scenario "A network engineer uses a summarised /16 route while one /24 subnet requires explicit inspection through another attachment", the proposed response is "Install and verify a more-specific route directing the regulated subnet to inspection". Which network behavior makes this suitable?
- Endpoint-specific DNS names and ENI addresses can change through resource replacement
- Longest-prefix selection allows deliberate exception routing when supported and governed
- Hybrid availability requires both AWS-side and customer-side failure-domain diversity
- Dynamic hybrid connectivity depends on compatible prefix filters and BGP path selection
Explanation
Correct Answer
B:Longest-prefix selection allows deliberate exception routing when supported and governed. This mechanism directly explains why the proposed change, install and verify a more-specific route directing the regulated subnet to inspection, fits this particular packet path or control requirement. Without it, one blanket summary can bypass a more-specific security path if exceptions are absent. A suitable verification is that the regulated /24 takes the intended inspection route while ordinary addresses use the summary.
Incorrect Answers
A:Endpoint-specific DNS names and ENI addresses can change through resource replacement explains a different case, for example when a VPC interface endpoint is deleted and recreated but scripts still target the former endpoint DNS name. In the current topology, the deciding factor is that longest-prefix selection allows deliberate exception routing when supported and governed; this choice therefore does not explain the specified remedy.
C:Hybrid availability requires both AWS-side and customer-side failure-domain diversity explains a different case, for example when a customer configures redundant links but a single customer gateway remains the only advertised next hop. In the current topology, the deciding factor is that longest-prefix selection allows deliberate exception routing when supported and governed; this choice therefore does not explain the specified remedy.
D:Dynamic hybrid connectivity depends on compatible prefix filters and BGP path selection explains a different case, for example when an on-premises application loses access to a VPC after a BGP policy change on the customer Direct Connect router. In the current topology, the deciding factor is that longest-prefix selection allows deliberate exception routing when supported and governed; this choice therefore does not explain the specified remedy.
Question 583
AWS architects plan to Correct bidirectional route advertisements and test the forward and return path for this requirement: A remote branch cannot reach AWS because its advertised VPC return prefix is absent from the corporate router. Which principle is MOST relevant?
- Public VIF reachability has its own route advertisement requirements separate from VPC private routing
- Transit VIFs enable supported Transit Gateway connectivity through Direct Connect gateways
- Successful hybrid communication requires both directions to have usable routes and compatible filters
- A Direct Connect LAG aggregates eligible physical connections with defined compatibility rules
Explanation
Correct Answer
C:Successful hybrid communication requires both directions to have usable routes and compatible filters. This mechanism directly explains why the proposed change, correct bidirectional route advertisements and test the forward and return path, fits this particular packet path or control requirement. Without it, a VPC route toward the branch alone cannot deliver response packets back on premises. A suitable verification is that bidirectional trace and BGP tables show both destination and reverse prefixes.
Incorrect Answers
A:Public VIF reachability has its own route advertisement requirements separate from VPC private routing explains a different case, for example when a company needs public AWS service API access across a Direct Connect public VIF but has not advertised eligible public prefixes. In the current topology, the deciding factor is that successful hybrid communication requires both directions to have usable routes and compatible filters; this choice therefore does not explain the specified remedy.
B:Transit VIFs enable supported Transit Gateway connectivity through Direct Connect gateways explains a different case, for example when a data center connects to a shared Transit Gateway through a Direct Connect gateway and the route table lacks the VPC destination. In the current topology, the deciding factor is that successful hybrid communication requires both directions to have usable routes and compatible filters; this choice therefore does not explain the specified remedy.
D:A Direct Connect LAG aggregates eligible physical connections with defined compatibility rules explains a different case, for example when a network team builds a link aggregation group with circuits of incompatible speed or port location. In the current topology, the deciding factor is that successful hybrid communication requires both directions to have usable routes and compatible filters; this choice therefore does not explain the specified remedy.
Question 584
A team faces this situation: A cloud egress inspection design allows application traffic to bypass a Network Firewall route in one availability zone. It proposes: Install complete per-AZ routes through intended firewall endpoints and test all affected subnets. What underlying networking principle BEST explains this decision?
- Security groups use stateful allow rules for supported resources and connections
- Centralized egress filtering is effective only when alternative unfiltered exits are removed
- Application-layer URL controls must be enforced where the HTTP request is inspected
- Availability-zone-specific routing can produce a partial bypass in centralized inspection designs
Explanation
Correct Answer
D:Availability-zone-specific routing can produce a partial bypass in centralized inspection designs. This mechanism directly explains why the proposed change, install complete per-AZ routes through intended firewall endpoints and test all affected subnets, fits this particular packet path or control requirement. Without it, one correctly configured route table does not prove every subnet follows inspection. A suitable verification is that negative and positive tests from each AZ traverse their matching firewall endpoint.
Incorrect Answers
A:Security groups use stateful allow rules for supported resources and connections explains a different case, for example when an EC2-based application needs inbound HTTPS from a trusted proxy but no public SSH connections. In the current topology, the deciding factor is that availability-zone-specific routing can produce a partial bypass in centralized inspection designs; this choice therefore does not explain the specified remedy.
B:Centralized egress filtering is effective only when alternative unfiltered exits are removed explains a different case, for example when a company routes all outbound traffic through a transparent proxy but direct routes to the NAT gateway remain available. In the current topology, the deciding factor is that availability-zone-specific routing can produce a partial bypass in centralized inspection designs; this choice therefore does not explain the specified remedy.
C:Application-layer URL controls must be enforced where the HTTP request is inspected explains a different case, for example when a regional edge application needs a custom allowlist for administrative URLs but the rule is attached only to an internal firewall. In the current topology, the deciding factor is that availability-zone-specific routing can produce a partial bypass in centralized inspection designs; this choice therefore does not explain the specified remedy.
Question 585
A networking team must correct the following AWS condition: An API response is slow only for overseas users despite healthy compute and regional ALB metrics. What is the MOST appropriate response?
- Compare edge CDN and Global Accelerator routing telemetry with regional network baselines
- Inspect ALB target health transitions and application readiness and warm-up settings
- Correlate AWS WAF sampled requests and logs with ALB access records
- Collect network path packet loss and retransmission metrics from both VPN endpoints
Explanation
Correct Answer
A:Compare edge CDN and Global Accelerator routing telemetry with regional network baselines. The stated configuration and business requirement call for this change because end-user latency includes DNS, internet path, edge, TLS, and origin time. Leaving the existing gap unresolved could mean that scaling origin CPU may not repair an inefficient global network entry path. Confirm the improvement by showing that a before-and-after client trace shows lower edge-to-origin or internet path latency.
Incorrect Answers
B:Inspect ALB target health transitions and application readiness and warm-up settings would address a different scenario, such as when an internal ALB becomes slow only during an autoscaling event and new targets receive requests before initialization. The present issue requires compare edge CDN and Global Accelerator routing telemetry with regional network baselines because the network path and control point are different; the alternative does not directly meet this requirement.
C:Correlate AWS WAF sampled requests and logs with ALB access records would address a different scenario, such as when a security analyst wants to inspect why traffic to an ALB is blocked only for one user-agent string. The present issue requires compare edge CDN and Global Accelerator routing telemetry with regional network baselines because the network path and control point are different; the alternative does not directly meet this requirement.
D:Collect network path packet loss and retransmission metrics from both VPN endpoints would address a different scenario, such as when an application sees packet loss after changing a VPN's customer equipment but AWS tunnel metrics show Up. The present issue requires compare edge CDN and Global Accelerator routing telemetry with regional network baselines because the network path and control point are different; the alternative does not directly meet this requirement.
Question 586
For the scenario "A network architecture team cannot summarize cloud address blocks because business units allocated overlapping private ranges", the proposed response is "Introduce IPAM governance and plan nonoverlapping VPC CIDR allocations or supported service proxies". Which network behavior makes this suitable?
- Shared VPCs centralize subnet administration while participants retain ownership of their supported resources
- CIDR overlap creates routing ambiguity and limits full-mesh private connectivity
- PrivateLink separates provider service publishing from consumer network route administration
- PrivateLink can publish selected service endpoints without requiring nonoverlapping full VPC routing
Explanation
Correct Answer
B:CIDR overlap creates routing ambiguity and limits full-mesh private connectivity. This mechanism directly explains why the proposed change, introduce IPAM governance and plan nonoverlapping VPC CIDR allocations or supported service proxies, fits this particular packet path or control requirement. Without it, adding more Transit Gateways cannot make overlapping destination addresses unambiguous. A suitable verification is that an address plan documents unique prefixes and new VPC allocation tests reject collisions.
Incorrect Answers
A:Shared VPCs centralize subnet administration while participants retain ownership of their supported resources explains a different case, for example when many application accounts share centrally owned subnet infrastructure but require isolated resource ownership. In the current topology, the deciding factor is that cIDR overlap creates routing ambiguity and limits full-mesh private connectivity; this choice therefore does not explain the specified remedy.
C:PrivateLink separates provider service publishing from consumer network route administration explains a different case, for example when two accounts need to expose a service but organization policy forbids consumer access to provider route tables. In the current topology, the deciding factor is that cIDR overlap creates routing ambiguity and limits full-mesh private connectivity; this choice therefore does not explain the specified remedy.
D:PrivateLink can publish selected service endpoints without requiring nonoverlapping full VPC routing explains a different case, for example when two teams have overlapping VPC CIDRs but must consume one narrowly defined service privately. In the current topology, the deciding factor is that cIDR overlap creates routing ambiguity and limits full-mesh private connectivity; this choice therefore does not explain the specified remedy.
Question 587
A team chooses to Use VPC Traffic Mirroring with a supported capture target and scoped filters after observing: A security analyst must inspect packet payload characteristics from supported EC2 network interfaces in a lab. Which result would BEST verify the change?
- Attachment state and route views match the approved network topology
- An aged sample remains available to authorized auditors after the required interval
- A controlled packet reaches the collector with the expected headers and payload
- Pre-change and post-change traces include consistent times, directions, and traffic classes
Explanation
Correct Answer
C:A controlled packet reaches the collector with the expected headers and payload. This directly tests whether the selected change, use VPC Traffic Mirroring with a supported capture target and scoped filters, achieved the intended network outcome. The key mechanism is that traffic Mirroring copies selected packet traffic instead of only summarized flow metadata. The incident or compliance risk being reduced was that flow Logs alone cannot show the packet bytes required for this authorized analysis.
Incorrect Answers
A:Attachment state and route views match the approved network topology might confirm another remediation, for instance when a hybrid transit network has many attachments and needs a central view of route reachability and network events. This question instead requires demonstrating that a controlled packet reaches the collector with the expected headers and payload. The alternative would not validate the selected network fix.
B:An aged sample remains available to authorized auditors after the required interval might confirm another remediation, for instance when a log pipeline uses short retention even though regulators require investigation records after employee departure. This question instead requires demonstrating that a controlled packet reaches the collector with the expected headers and payload. The alternative would not validate the selected network fix.
D:Pre-change and post-change traces include consistent times, directions, and traffic classes might confirm another remediation, for instance when a business needs a defensible hybrid network baseline for latency, packet loss, and utilization before adding Direct Connect. This question instead requires demonstrating that a controlled packet reaches the collector with the expected headers and payload. The alternative would not validate the selected network fix.
Question 588
The team addressed this problem: A news publisher wants different images cached by device class but never by irrelevant tracking parameters. Which observation BEST demonstrates the required result?
- Existing endpoint configuration remains constant while new UDP traffic shifts to a healthy Region
- Clients retain the same advertised addresses when the unhealthy Region loses traffic
- The CloudFront URL serves expected assets and direct anonymous S3 GET is denied
- A/B mobile image variants remain distinct while tracking-only requests share cache objects
Explanation
Correct Answer
D:A/B mobile image variants remain distinct while tracking-only requests share cache objects. This directly tests whether the selected change, define CloudFront cache policies that vary only on required headers and query strings, achieved the intended network outcome. The key mechanism is that cache-key selection trades content correctness against fragmentation and cache efficiency. The incident or compliance risk being reduced was that including every query parameter unnecessarily reduces edge cache reuse.
Incorrect Answers
A:Existing endpoint configuration remains constant while new UDP traffic shifts to a healthy Region might confirm another remediation, for instance when a multiplayer client cannot tolerate DNS change delays during regional failure and uses UDP transport. This question instead requires demonstrating that a/B mobile image variants remain distinct while tracking-only requests share cache objects. The alternative would not validate the selected network fix.
B:Clients retain the same advertised addresses when the unhealthy Region loses traffic might confirm another remediation, for instance when a trading client needs static anycast IP addresses and TCP endpoint failover across Regions. This question instead requires demonstrating that a/B mobile image variants remain distinct while tracking-only requests share cache objects. The alternative would not validate the selected network fix.
C:The CloudFront URL serves expected assets and direct anonymous S3 GET is denied might confirm another remediation, for instance when an S3 static asset origin behind CloudFront must deny direct anonymous bucket reads. This question instead requires demonstrating that a/B mobile image variants remain distinct while tracking-only requests share cache objects. The alternative would not validate the selected network fix.
Question 589
For this networking situation, A network engineer wants automated proof that a security group and route table permit an intended VPC path, the team applies "Use VPC Reachability Analyzer to examine the configuration path for the source and destination". Which validation is strongest?
- The analyzer shows the intended path and identifies the removed misconfiguration
- A simulated tunnel outage generates an actionable notification tied to the tunnel
- Attachment state and route views match the approved network topology
- An intentional backend error is visible with the expected request and target status
Explanation
Correct Answer
A:The analyzer shows the intended path and identifies the removed misconfiguration. This directly tests whether the selected change, use VPC Reachability Analyzer to examine the configuration path for the source and destination, achieved the intended network outcome. The key mechanism is that reachability Analyzer models AWS configuration paths and identifies blockers without creating test packets. The incident or compliance risk being reduced was that a successful configuration analysis cannot guarantee application health or external network behavior.
Incorrect Answers
B:A simulated tunnel outage generates an actionable notification tied to the tunnel might confirm another remediation, for instance when an operations team wants alerts when a VPN tunnel state changes and loses redundant connectivity. This question instead requires demonstrating that the analyzer shows the intended path and identifies the removed misconfiguration. The alternative would not validate the selected network fix.
C:Attachment state and route views match the approved network topology might confirm another remediation, for instance when a hybrid transit network has many attachments and needs a central view of route reachability and network events. This question instead requires demonstrating that the analyzer shows the intended path and identifies the removed misconfiguration. The alternative would not validate the selected network fix.
D:An intentional backend error is visible with the expected request and target status might confirm another remediation, for instance when a multi-region API owner wants to distinguish ALB client errors from backend target failures. This question instead requires demonstrating that the analyzer shows the intended path and identifies the removed misconfiguration. The alternative would not validate the selected network fix.
Question 590
Following remediation of "A Route 53 failover record references a health check that tests only the landing page while the API path is broken", what evidence MOST directly establishes that it works?
- Consumer DNS lookups return private endpoint addresses and test calls stay within approved connectivity
- Simulated API failure moves DNS selection to a verified healthy endpoint
- Large and ordinary DNS queries return successfully from the approved corporate resolver
- On-premises queries arrive on the endpoint and resolve intended private AWS names
Explanation
Correct Answer
B:Simulated API failure moves DNS selection to a verified healthy endpoint. This directly tests whether the selected change, configure health checks or calculated checks that reflect the actual application requirement, achieved the intended network outcome. The key mechanism is that dNS-based failover quality depends on application-aware endpoint health evidence. The incident or compliance risk being reduced was that a healthy static homepage can cause DNS to keep advertising a failed API.
Incorrect Answers
A:Consumer DNS lookups return private endpoint addresses and test calls stay within approved connectivity might confirm another remediation, for instance when an internal API is exposed by PrivateLink but consumers resolve its hostname to a public ALB. This question instead requires demonstrating that simulated API failure moves DNS selection to a verified healthy endpoint. The alternative would not validate the selected network fix.
C:Large and ordinary DNS queries return successfully from the approved corporate resolver might confirm another remediation, for instance when a new on-premises BIND server is allowed to send queries to Route 53 Resolver inbound endpoint over UDP but TCP responses time out. This question instead requires demonstrating that simulated API failure moves DNS selection to a verified healthy endpoint. The alternative would not validate the selected network fix.
D:On-premises queries arrive on the endpoint and resolve intended private AWS names might confirm another remediation, for instance when an on-premises DNS appliance forwards internal AWS names to a VPC but has no routable destination for the VPC Resolver endpoint IPs. This question instead requires demonstrating that simulated API failure moves DNS selection to a verified healthy endpoint. The alternative would not validate the selected network fix.