AWS Certified Advanced Networking - Specialty ANS-C01 Practice Test 15
Question 140
The team addressed this problem: An internal ALB becomes slow only during an autoscaling event and new targets receive requests before initialization. Which observation BEST demonstrates the required result?
- A test workload's cross-region bytes and attributed cost change together
- A controlled burst is visible in the chosen high-resolution observation source
- Bidirectional loss and packet-size measurements identify the faulty network segment
- Target health remains accurate during scale-up and requests complete during warm-up
Explanation
Correct Answer
D:Target health remains accurate during scale-up and requests complete during warm-up. This directly tests whether the selected change, inspect ALB target health transitions and application readiness and warm-up settings, achieved the intended network outcome. The key mechanism is that load balancer request distribution depends on backend health and lifecycle coordination. The incident or compliance risk being reduced was that a new instance in Running state may not yet be ready for live transactions.
Incorrect Answers
A:A test workload's cross-region bytes and attributed cost change together might confirm another remediation, for instance when an engineering group wants to attribute inter-region data transfer growth to one service and routing path. This question instead requires demonstrating that target health remains accurate during scale-up and requests complete during warm-up. The alternative would not validate the selected network fix.
B:A controlled burst is visible in the chosen high-resolution observation source might confirm another remediation, for instance when a company is investigating short bursts of traffic that disappear from five-minute aggregated metrics. This question instead requires demonstrating that target health remains accurate during scale-up and requests complete during warm-up. The alternative would not validate the selected network fix.
C:Bidirectional loss and packet-size measurements identify the faulty network segment might confirm another remediation, for instance when an application sees packet loss after changing a VPN's customer equipment but AWS tunnel metrics show Up. This question instead requires demonstrating that target health remains accurate during scale-up and requests complete during warm-up. The alternative would not validate the selected network fix.
Question 141
A networking team must correct the following AWS condition: A team configured a Direct Connect private VIF but selected the wrong AWS account's virtual private gateway. What is the MOST appropriate response?
- Associate the VIF or Direct Connect gateway with the supported target gateway and verify ownership
- Correct bidirectional route advertisements and test the forward and return path
- Add the required independent location and customer device paths instead of only separate logical sessions
- Check the customer gateway ASN, configured peer addresses and permitted TCP BGP sessions
Explanation
Correct Answer
A:Associate the VIF or Direct Connect gateway with the supported target gateway and verify ownership. The stated configuration and business requirement call for this change because gateway attachments and association permissions govern which VPC receives hybrid prefixes. Leaving the existing gap unresolved could mean that a correctly tagged VLAN cannot deliver traffic to an unrelated gateway. Confirm the improvement by showing that attachment associations show the expected AWS resource and route reachability.
Incorrect Answers
B:Correct bidirectional route advertisements and test the forward and return path would address a different scenario, such as when a remote branch cannot reach AWS because its advertised VPC return prefix is absent from the corporate router. The present issue requires associate the VIF or Direct Connect gateway with the supported target gateway and verify ownership because the network path and control point are different; the alternative does not directly meet this requirement.
C:Add the required independent location and customer device paths instead of only separate logical sessions would address a different scenario, such as when a company wants a redundant connection but its two hosted Direct Connect links terminate in the same colocation facility. The present issue requires associate the VIF or Direct Connect gateway with the supported target gateway and verify ownership because the network path and control point are different; the alternative does not directly meet this requirement.
D:Check the customer gateway ASN, configured peer addresses and permitted TCP BGP sessions would address a different scenario, such as when an on-premises site sends traffic to AWS over VPN but the customer router rejects expected BGP adjacency. The present issue requires associate the VIF or Direct Connect gateway with the supported target gateway and verify ownership because the network path and control point are different; the alternative does not directly meet this requirement.
Question 142
What failure mode is MOST relevant if a team ignores this issue: An application uses private DNS for its service but clients fail TLS validation because the certificate contains only the public hostname?
- A secure VPN between networks does not protect users from insecure application redirects
- A private endpoint does not bypass normal TLS hostname validation
- Encrypting the browser connection alone leaves the CloudFront-to-origin hop unprotected
- Assuming Direct Connect inherently encrypts payloads can violate confidentiality requirements
Explanation
Correct Answer
B:A private endpoint does not bypass normal TLS hostname validation. The missing control matters because dNS naming and certificate identity must match regardless of whether the IP is private. The appropriate corrective action is to align private service names with valid certificate SANs or approved client naming conventions. To check the outcome, verify that clients resolve the private name and validate a matching certificate chain.
Incorrect Answers
A:A secure VPN between networks does not protect users from insecure application redirects can be a real consequence when a customer VPN carries application traffic securely but an application returns sensitive session tokens through an unauthenticated HTTP redirect. Here the relevant failure is that a private endpoint does not bypass normal TLS hostname validation. The alternative names a different failure mode and does not best account for the stated condition.
C:Encrypting the browser connection alone leaves the CloudFront-to-origin hop unprotected can be a real consequence when a public website terminates HTTPS at CloudFront but uses HTTP to fetch sensitive dynamic data from its origin. Here the relevant failure is that a private endpoint does not bypass normal TLS hostname validation. The alternative names a different failure mode and does not best account for the stated condition.
D:Assuming Direct Connect inherently encrypts payloads can violate confidentiality requirements can be a real consequence when a financial firm uses Direct Connect for regulated traffic but needs cryptographic protection while crossing the private circuit. Here the relevant failure is that a private endpoint does not bypass normal TLS hostname validation. The alternative names a different failure mode and does not best account for the stated condition.
Question 143
AWS architects plan to Offer the service through PrivateLink endpoint service backed by an NLB where supported for this requirement: A consumer needs to reach an application by private VPC endpoint across accounts without full IP connectivity. Which principle is MOST relevant?
- TLS termination at a load balancer does not automatically encrypt every backend hop
- Gateway Load Balancer uses GENEVE to distribute network flows to security appliance targets
- PrivateLink exposes selected services through interface endpoints without general VPC routing
- Load balancer target type determines how requests are addressed to backends
Explanation
Correct Answer
C:PrivateLink exposes selected services through interface endpoints without general VPC routing. This mechanism directly explains why the proposed change, offer the service through PrivateLink endpoint service backed by an NLB where supported, fits this particular packet path or control requirement. Without it, full VPC peering adds broader address reachability than the single-service requirement. A suitable verification is that consumer endpoint calls succeed and unrelated provider network addresses remain unreachable.
Incorrect Answers
A:TLS termination at a load balancer does not automatically encrypt every backend hop explains a different case, for example when an application uses an ALB with HTTPS listeners but must ensure encryption continues to backend instances. In the current topology, the deciding factor is that privateLink exposes selected services through interface endpoints without general VPC routing; this choice therefore does not explain the specified remedy.
B:Gateway Load Balancer uses GENEVE to distribute network flows to security appliance targets explains a different case, for example when a fleet of virtual firewalls must receive traffic with flow symmetry and transparent appliance insertion. In the current topology, the deciding factor is that privateLink exposes selected services through interface endpoints without general VPC routing; this choice therefore does not explain the specified remedy.
D:Load balancer target type determines how requests are addressed to backends explains a different case, for example when an application uses a target group with the wrong registered target type for its container network mode. In the current topology, the deciding factor is that privateLink exposes selected services through interface endpoints without general VPC routing; this choice therefore does not explain the specified remedy.
Question 144
An AWS network architect encounters this situation: A security reviewer needs a repeatable audit that production VPC paths cannot reach a prohibited subnet. Which change BEST meets the documented requirement?
- Enable suitable AWS Config recording and network-related compliance evaluations
- Enable supported WAF logs or sampled requests with redaction of sensitive fields
- Correlate CloudTrail changes, VPC flow logs and application telemetry by time and resource identifiers
- Run Reachability Analyzer negative-path tests after relevant network changes
Explanation
Correct Answer
D:Run Reachability Analyzer negative-path tests after relevant network changes. The stated configuration and business requirement call for this change because reachability Analyzer can validate modeled AWS configuration paths against intended deny reachability. Leaving the existing gap unresolved could mean that a blocked ping alone cannot distinguish security policy from application failure. Confirm the improvement by showing that a deliberate prohibited-path analysis reports no supported reachability.
Incorrect Answers
A:Enable suitable AWS Config recording and network-related compliance evaluations would address a different scenario, such as when an auditor asks for evidence that prohibited network routes are detected if changed outside IaC. The present issue requires run Reachability Analyzer negative-path tests after relevant network changes because the network path and control point are different; the alternative does not directly meet this requirement.
B:Enable supported WAF logs or sampled requests with redaction of sensitive fields would address a different scenario, such as when a WAF web ACL blocks some requests unexpectedly and the team only has total request counts. The present issue requires run Reachability Analyzer negative-path tests after relevant network changes because the network path and control point are different; the alternative does not directly meet this requirement.
C:Correlate CloudTrail changes, VPC flow logs and application telemetry by time and resource identifiers would address a different scenario, such as when a SOC wants to distinguish whether a network outage followed a VPC routing update or an application deployment. The present issue requires run Reachability Analyzer negative-path tests after relevant network changes because the network path and control point are different; the alternative does not directly meet this requirement.
Question 145
A network review finds: A remote office experiences internet variability to the selected AWS VPN region and wants improved entry routing. Which consequence MOST clearly explains the need for a fix?
- An accelerated VPN endpoint does not remove all customer last-mile and tunnel constraints
- Selecting a private VIF does not by itself authorize routing to all AWS public IP services
- Operating only one tunnel sacrifices built-in redundancy during endpoint maintenance
- A generic Site-to-Site VPN connection does not provide the same managed GRE Connect pattern
Explanation
Correct Answer
A:An accelerated VPN endpoint does not remove all customer last-mile and tunnel constraints. The missing control matters because accelerated VPN can use AWS global network to reduce some internet-path variability. The appropriate corrective action is to assess accelerated Site-to-Site VPN compatibility and route to the nearest AWS edge. To check the outcome, verify that measured sustained tunnel latency and loss improve under matching supported conditions.
Incorrect Answers
B:Selecting a private VIF does not by itself authorize routing to all AWS public IP services can be a real consequence when a corporate office needs AWS public service endpoints over a dedicated public routing path without private VPC address exchange. Here the relevant failure is that an accelerated VPN endpoint does not remove all customer last-mile and tunnel constraints. The alternative names a different failure mode and does not best account for the stated condition.
C:Operating only one tunnel sacrifices built-in redundancy during endpoint maintenance can be a real consequence when a company needs a redundant Site-to-Site VPN and both standard tunnels terminate on customer gateway devices. Here the relevant failure is that an accelerated VPN endpoint does not remove all customer last-mile and tunnel constraints. The alternative names a different failure mode and does not best account for the stated condition.
D:A generic Site-to-Site VPN connection does not provide the same managed GRE Connect pattern can be a real consequence when a distributed branch solution needs SD-WAN appliance integration with Transit Gateway using overlay tunnels. Here the relevant failure is that an accelerated VPN endpoint does not remove all customer last-mile and tunnel constraints. The alternative names a different failure mode and does not best account for the stated condition.
Question 146
For the scenario "A Direct Connect path carries small pings but large data transfers repeatedly stall after a network change", the proposed response is "Check MTU and path-MTU discovery across Direct Connect, VPC and overlay hops". Which network behavior makes this suitable?
- Reachability Analyzer identifies configured hop restrictions but does not send real user traffic
- Packet-size mismatches can create black holes when required ICMP feedback is filtered
- Transit route analysis connects gateway route configuration to observed flow paths
- Network interface allocation can be limited by available subnet addresses and service quotas
Explanation
Correct Answer
B:Packet-size mismatches can create black holes when required ICMP feedback is filtered. This mechanism directly explains why the proposed change, check MTU and path-MTU discovery across Direct Connect, VPC and overlay hops, fits this particular packet path or control requirement. Without it, application retries will not consistently fix incompatible jumbo-frame or tunnel settings. A suitable verification is that controlled payload-size tests identify a stable maximum that supports full transfers.
Incorrect Answers
A:Reachability Analyzer identifies configured hop restrictions but does not send real user traffic explains a different case, for example when two EC2 instances cannot connect and VPC Reachability Analyzer reports a blocked security group rule. In the current topology, the deciding factor is that packet-size mismatches can create black holes when required ICMP feedback is filtered; this choice therefore does not explain the specified remedy.
C:Transit route analysis connects gateway route configuration to observed flow paths explains a different case, for example when a multi-VPC application shows intermittent failure only when crossing a Transit Gateway after a recent route change. In the current topology, the deciding factor is that packet-size mismatches can create black holes when required ICMP feedback is filtered; this choice therefore does not explain the specified remedy.
D:Network interface allocation can be limited by available subnet addresses and service quotas explains a different case, for example when a subnet has enough addresses on paper but ECS tasks cannot create ENIs in one availability zone. In the current topology, the deciding factor is that packet-size mismatches can create black holes when required ICMP feedback is filtered; this choice therefore does not explain the specified remedy.
Question 147
During an AWS network design review, the team observes: A web administrator changed a DNS record but some users still reach an old destination for several minutes. Which solution BEST resolves the gap?
- Review matching private-zone and Resolver-rule specificity before adding another rule
- Retain VPC DNS resolution support and configure the appropriate private hosted zone associations
- Check resolver caching and lower authoritative TTL ahead of the planned migration
- Associate authorized cross-account VPCs with the private hosted zone using supported authorization
Explanation
Correct Answer
C:Check resolver caching and lower authoritative TTL ahead of the planned migration. The stated configuration and business requirement call for this change because positive DNS response caching persists for the TTL observed before a change. Leaving the existing gap unresolved could mean that changing an authoritative record does not immediately invalidate remote recursive caches. Confirm the improvement by showing that repeated queries converge after prior TTL expiry and the cutover timeline matches cache behavior.
Incorrect Answers
A:Review matching private-zone and Resolver-rule specificity before adding another rule would address a different scenario, such as when two private hosted zones share a suffix and a resolver rule has a more-specific matching domain. The present issue requires check resolver caching and lower authoritative TTL ahead of the planned migration because the network path and control point are different; the alternative does not directly meet this requirement.
B:Retain VPC DNS resolution support and configure the appropriate private hosted zone associations would address a different scenario, such as when an EC2 application in a VPC must resolve both internal records and external internet domain names. The present issue requires check resolver caching and lower authoritative TTL ahead of the planned migration because the network path and control point are different; the alternative does not directly meet this requirement.
D:Associate authorized cross-account VPCs with the private hosted zone using supported authorization would address a different scenario, such as when multiple accounts require the same private hosted zone but each VPC sits outside the zone owner's account. The present issue requires check resolver caching and lower authoritative TTL ahead of the planned migration because the network path and control point are different; the alternative does not directly meet this requirement.
Question 148
A team faces this situation: An internal review needs proof that the same TCP conversation was observed at an inspection point during a suspected incident. It proposes: Configure supported VPC Traffic Mirroring with scoped capture filters to a protected target. What underlying networking principle BEST explains this decision?
- Alert and flow logs indicate how the firewall handled matching network traffic
- Flow logs support configurable fields and aggregation for network metadata analysis
- Continuous security governance requires auditable exceptions and predictable expiry
- Traffic mirroring provides packets suitable for protocol-level inspection when permissions allow
Explanation
Correct Answer
D:Traffic mirroring provides packets suitable for protocol-level inspection when permissions allow. This mechanism directly explains why the proposed change, configure supported VPC Traffic Mirroring with scoped capture filters to a protected target, fits this particular packet path or control requirement. Without it, cloudTrail management events do not contain TCP packet payload evidence. A suitable verification is that a controlled session yields packets and connection metadata at the capture target.
Incorrect Answers
A:Alert and flow logs indicate how the firewall handled matching network traffic explains a different case, for example when a firewall deployment collects rule hit counts but compliance also requires knowing whether packets were actually dropped. In the current topology, the deciding factor is that traffic mirroring provides packets suitable for protocol-level inspection when permissions allow; this choice therefore does not explain the specified remedy.
B:Flow logs support configurable fields and aggregation for network metadata analysis explains a different case, for example when a response team has VPC Flow Logs but cannot distinguish accepted and rejected internet attempts by source subnet. In the current topology, the deciding factor is that traffic mirroring provides packets suitable for protocol-level inspection when permissions allow; this choice therefore does not explain the specified remedy.
C:Continuous security governance requires auditable exceptions and predictable expiry explains a different case, for example when a regulated business uses Firewall Manager but resource exceptions have no owner or expiration date. In the current topology, the deciding factor is that traffic mirroring provides packets suitable for protocol-level inspection when permissions allow; this choice therefore does not explain the specified remedy.
Question 149
For this networking situation, A company needs to preserve compliance evidence from ALB, CloudFront, and Network Firewall in one protected location, the team applies "Centralize eligible service logs to approved S3 or log ingestion with scoped retention and encryption". Which validation is strongest?
- A correlated test request appears in the appropriate normalized log sources
- A deliberate prohibited-path analysis reports no supported reachability
- A synthetic match produces the expected rule ID without logging sensitive secrets
- The modification appears with actor, API action and request metadata
Explanation
Correct Answer
A:A correlated test request appears in the appropriate normalized log sources. This directly tests whether the selected change, centralize eligible service logs to approved S3 or log ingestion with scoped retention and encryption, achieved the intended network outcome. The key mechanism is that different AWS networking services emit different schemas that require a governed collection architecture. The incident or compliance risk being reduced was that only collecting VPC Flow Logs omits request-level and firewall-rule decisions.
Incorrect Answers
B:A deliberate prohibited-path analysis reports no supported reachability might confirm another remediation, for instance when a security reviewer needs a repeatable audit that production VPC paths cannot reach a prohibited subnet. This question instead requires demonstrating that a correlated test request appears in the appropriate normalized log sources. The alternative would not validate the selected network fix.
C:A synthetic match produces the expected rule ID without logging sensitive secrets might confirm another remediation, for instance when a WAF web ACL blocks some requests unexpectedly and the team only has total request counts. This question instead requires demonstrating that a correlated test request appears in the appropriate normalized log sources. The alternative would not validate the selected network fix.
D:The modification appears with actor, API action and request metadata might confirm another remediation, for instance when an AWS account has no trace of who modified a Route 53 Resolver forwarding rule during a DNS incident. This question instead requires demonstrating that a correlated test request appears in the appropriate normalized log sources. The alternative would not validate the selected network fix.
Question 150
For the scenario "An application serves large personalized private documents and must prevent one user's cached response reaching another", the proposed response is "Use private cache behaviors or disable caching for sensitive identity-dependent responses". Which network behavior makes this suitable?
- Global Accelerator steering uses stable anycast IPs rather than relying solely on resolver TTL
- Shared edge caches require cache keys and response policies that respect authorization context
- Geographic access controls and origin selection must align with legal data location requirements
- Global Accelerator manages healthy regional endpoint selection independently of customer DNS caches
Explanation
Correct Answer
B:Shared edge caches require cache keys and response policies that respect authorization context. This mechanism directly explains why the proposed change, use private cache behaviors or disable caching for sensitive identity-dependent responses, fits this particular packet path or control requirement. Without it, caching authenticated content under a shared key can disclose another customer's document. A suitable verification is that cross-user tests cannot retrieve each other's objects while authorized retrieval succeeds.
Incorrect Answers
A:Global Accelerator steering uses stable anycast IPs rather than relying solely on resolver TTL explains a different case, for example when a multiplayer client cannot tolerate DNS change delays during regional failure and uses UDP transport. In the current topology, the deciding factor is that shared edge caches require cache keys and response policies that respect authorization context; this choice therefore does not explain the specified remedy.
C:Geographic access controls and origin selection must align with legal data location requirements explains a different case, for example when a media business has regional data residency rules for viewers and cannot send all users to one origin. In the current topology, the deciding factor is that shared edge caches require cache keys and response policies that respect authorization context; this choice therefore does not explain the specified remedy.
D:Global Accelerator manages healthy regional endpoint selection independently of customer DNS caches explains a different case, for example when a public application has two regional ALBs and wants traffic to fail away from an entire unhealthy application Region. In the current topology, the deciding factor is that shared edge caches require cache keys and response policies that respect authorization context; this choice therefore does not explain the specified remedy.