Question 740
A network API is rate-limited, and a retry script sends immediate repeated POSTs without respecting status 429, creating duplicate configuration attempts. During troubleshooting: Bursting retries overwhelm the controller while some POST requests complete twice. Which underlying cause best explains the recorded behavior?
- Management traffic is processed in the CPU and lacks suitable control-plane rate controls.
- The API bearer token was embedded in accessible source code and never revoked.
- The client treats rate limiting as an immediate failure loop without safe retry/idempotency design.
- The API client disables TLS peer verification and cannot authenticate the server.
Explanation
Correct Answer
C:The actual technical cause is: The client treats rate limiting as an immediate failure loop without safe retry/idempotency design. It specifically explains the observation: bursting retries overwhelm the controller while some POST requests complete twice. The correcting configuration is: implement bounded exponential backoff, honor Retry-After where provided and use idempotent operation handling.
Incorrect Answers
A:That diagnosis is supported by a different symptom: A small volume of repeated SNMP requests causes control-plane slowdown without link saturation. Here the recorded observation is: bursting retries overwhelm the controller while some POST requests complete twice. The applicable cause is: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design.
B:That diagnosis is supported by a different symptom: An unauthorized collaborator reuses the committed token to call management APIs. Here the recorded observation is: bursting retries overwhelm the controller while some POST requests complete twice. The applicable cause is: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design.
D:That diagnosis is supported by a different symptom: A client ignores invalid certificates and sends credentials to an untrusted management endpoint. Here the recorded observation is: bursting retries overwhelm the controller while some POST requests complete twice. The applicable cause is: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design.
Question 741
A network API is rate-limited, and a retry script sends immediate repeated POSTs without respecting status 429, creating duplicate configuration attempts. The initial change is: Implement bounded exponential backoff, honor Retry-After where provided and use idempotent operation handling. Which continuing control most directly prevents a recurrence of the documented problem: Bursting retries overwhelm the controller while some POST requests complete twice.
- Coordinate polling frequency and CoPP rates rather than masking telemetry failure.
- Require token expiry, scoped service identities, secret scanning and rotation processes.
- Rotate certificates and pin/validate appropriate CAs without disabling TLS checks.
- Track API request limits, response codes and correlation IDs in automation logging.
Explanation
Correct Answer
D:The continuing protective control is: Track API request limits, response codes and correlation IDs in automation logging. This addresses the underlying failure mechanism: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design. The corresponding operational check is: simulate HTTP429 responses and verify the script delays retries without duplicate objects.
Incorrect Answers
A:That control reduces a separate risk: Management traffic is processed in the CPU and lacks suitable control-plane rate controls. For the described design, the recurring risk arises from: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design. The specific required safeguard is: track API request limits, response codes and correlation IDs in automation logging.
B:That control reduces a separate risk: The API bearer token was embedded in accessible source code and never revoked. For the described design, the recurring risk arises from: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design. The specific required safeguard is: track API request limits, response codes and correlation IDs in automation logging.
C:That control reduces a separate risk: The API client disables TLS peer verification and cannot authenticate the server. For the described design, the recurring risk arises from: the client treats rate limiting as an immediate failure loop without safe retry/idempotency design. The specific required safeguard is: track API request limits, response codes and correlation IDs in automation logging.
Question 742
A branch network needs to inspect malicious ingress traffic while retaining a layered defense rather than relying on one perimeter ACL alone. The incident evidence is: A compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter. Which targeted configuration or design change best addresses the failure?
- Use supported IEEE 802.1AE MACsec link encryption and compatible key agreement on both switch endpoints.
- Use a suitable next-generation firewall with application awareness and permitted TLS inspection controls.
- Use defense-in-depth controls such as segmented access, threat inspection and least-privilege policy at the relevant boundaries.
- Enable the supported SGT propagation or mapping mechanism across the relevant transit path.
Explanation
Correct Answer
C:The required correction is: Use defense-in-depth controls such as segmented access, threat inspection and least-privilege policy at the relevant boundaries. The underlying failure mechanism is: No internal segmentation or layered threat controls protect east-west movement. Verify success by carrying out this direct test: test a simulated malicious flow through ingress inspection and segmentation controls.
Incorrect Answers
A:The Ethernet hop lacks functioning MACsec encryption despite ordinary VLAN segmentation. No internal segmentation or layered threat controls protect east-west movement.
B:Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context. No internal segmentation or layered threat controls protect east-west movement.
D:The transit path does not carry or reconstruct security group tags to the enforcement point. No internal segmentation or layered threat controls protect east-west movement.
Question 743
A branch network needs to inspect malicious ingress traffic while retaining a layered defense rather than relying on one perimeter ACL alone. The proposed remedy is: Use defense-in-depth controls such as segmented access, threat inspection and least-privilege policy at the relevant boundaries. Which observation would most directly confirm that remedy works as intended?
- Test a known allowed business app and a blocked malicious signature in the approved inspection scope.
- Test a simulated malicious flow through ingress inspection and segmentation controls.
- Inspect tag values at ingress and enforcement devices for a controlled endpoint flow.
- Capture frames on the physical link and confirm encrypted MACsec data with authorized peers maintaining connectivity.
Explanation
Correct Answer
B:The decisive acceptance observation is: Test a simulated malicious flow through ingress inspection and segmentation controls. This tests the working mechanism, while the original incident was: a compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter.
Incorrect Answers
A:This test measures a different behavior: Test a known allowed business app and a blocked malicious signature in the approved inspection scope. It does not establish the target outcome. For the documented fault, the direct acceptance test is: test a simulated malicious flow through ingress inspection and segmentation controls.
C:This test measures a different behavior: Inspect tag values at ingress and enforcement devices for a controlled endpoint flow. It does not establish the target outcome. For the documented fault, the direct acceptance test is: test a simulated malicious flow through ingress inspection and segmentation controls.
D:This test measures a different behavior: Capture frames on the physical link and confirm encrypted MACsec data with authorized peers maintaining connectivity. It does not establish the target outcome. For the documented fault, the direct acceptance test is: test a simulated malicious flow through ingress inspection and segmentation controls.
Question 744
A branch network needs to inspect malicious ingress traffic while retaining a layered defense rather than relying on one perimeter ACL alone. During troubleshooting: A compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter. Which underlying cause best explains the recorded behavior?
- The Ethernet hop lacks functioning MACsec encryption despite ordinary VLAN segmentation.
- The transit path does not carry or reconstruct security group tags to the enforcement point.
- Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context.
- No internal segmentation or layered threat controls protect east-west movement.
Explanation
Correct Answer
D:The actual technical cause is: No internal segmentation or layered threat controls protect east-west movement. It specifically explains the observation: a compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter. The correcting configuration is: use defense-in-depth controls such as segmented access, threat inspection and least-privilege policy at the relevant boundaries.
Incorrect Answers
A:That diagnosis is supported by a different symptom: A passive tap reads sensitive unencrypted payloads on the supposedly protected switch-to-switch wire. Here the recorded observation is: a compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter. The applicable cause is: no internal segmentation or layered threat controls protect east-west movement.
B:That diagnosis is supported by a different symptom: The destination SGACL treats all traffic as unknown SGT despite correct access-edge classification. Here the recorded observation is: a compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter. The applicable cause is: no internal segmentation or layered threat controls protect east-west movement.
C:That diagnosis is supported by a different symptom: A basic destination-port ACL permits both harmless and malicious traffic on TCP443. Here the recorded observation is: a compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter. The applicable cause is: no internal segmentation or layered threat controls protect east-west movement.
Question 745
A branch network needs to inspect malicious ingress traffic while retaining a layered defense rather than relying on one perimeter ACL alone. The initial change is: Use defense-in-depth controls such as segmented access, threat inspection and least-privilege policy at the relevant boundaries. Which continuing control most directly prevents a recurrence of the documented problem: A compromised workstation reaches sensitive management hosts after bypassing the one permissive edge filter.
- Manage MACsec keys/certificates and link compatibility during interface or optics changes.
- Audit SGT propagation when traversing mixed-capability fabric and firewalls.
- Maintain threat signatures, certificate/inspection policy and application allowlists.
- Review multiple boundary layers and threat logging after new application deployments.
Explanation
Correct Answer
D:The continuing protective control is: Review multiple boundary layers and threat logging after new application deployments. This addresses the underlying failure mechanism: no internal segmentation or layered threat controls protect east-west movement. The corresponding operational check is: test a simulated malicious flow through ingress inspection and segmentation controls.
Incorrect Answers
A:That control reduces a separate risk: The Ethernet hop lacks functioning MACsec encryption despite ordinary VLAN segmentation. For the described design, the recurring risk arises from: no internal segmentation or layered threat controls protect east-west movement. The specific required safeguard is: review multiple boundary layers and threat logging after new application deployments.
B:That control reduces a separate risk: The transit path does not carry or reconstruct security group tags to the enforcement point. For the described design, the recurring risk arises from: no internal segmentation or layered threat controls protect east-west movement. The specific required safeguard is: review multiple boundary layers and threat logging after new application deployments.
C:That control reduces a separate risk: Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context. For the described design, the recurring risk arises from: no internal segmentation or layered threat controls protect east-west movement. The specific required safeguard is: review multiple boundary layers and threat logging after new application deployments.
Question 746
Corporate endpoints connect to a trusted VLAN but unmanaged devices can join with no posture assessment or isolation. The incident evidence is: An unmanaged infected laptop obtains the same internal reachability as managed devices. Which targeted configuration or design change best addresses the failure?
- Use Cisco TrustSec security group tags and SGACL enforcement where the platform and design support it.
- Use supported IEEE 802.1AE MACsec link encryption and compatible key agreement on both switch endpoints.
- Introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately.
- Enable the supported SGT propagation or mapping mechanism across the relevant transit path.
Explanation
Correct Answer
C:The required correction is: Introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately. The underlying failure mechanism is: Endpoint admission and posture enforcement are absent at access boundaries. Verify success by carrying out this direct test: connect compliant and noncompliant test endpoints and inspect the different authorized access results.
Incorrect Answers
A:The needed correction is to introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately.
B:Using supported IEEE 802.1AE MACsec link encryption and compatible key agreement on both switch endpoints would not address the need for introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately.
D:Enabling the supported SGT propagation or mapping mechanism across the relevant transit path would not address the need for introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately.
Question 747
Corporate endpoints connect to a trusted VLAN but unmanaged devices can join with no posture assessment or isolation. The proposed remedy is: Introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately. Which observation would most directly confirm that remedy works as intended?
- Test the intended source/destination SGT pair across VLAN changes and check policy counters.
- Connect compliant and noncompliant test endpoints and inspect the different authorized access results.
- Inspect tag values at ingress and enforcement devices for a controlled endpoint flow.
- Capture frames on the physical link and confirm encrypted MACsec data with authorized peers maintaining connectivity.
Explanation
Correct Answer
B:The decisive acceptance observation is: Connect compliant and noncompliant test endpoints and inspect the different authorized access results. This tests the working mechanism, while the original incident was: an unmanaged infected laptop obtains the same internal reachability as managed devices.
Incorrect Answers
A:This test measures a different behavior: Test the intended source/destination SGT pair across VLAN changes and check policy counters. It does not establish the target outcome. For the documented fault, the direct acceptance test is: connect compliant and noncompliant test endpoints and inspect the different authorized access results.
C:This test measures a different behavior: Inspect tag values at ingress and enforcement devices for a controlled endpoint flow. It does not establish the target outcome. For the documented fault, the direct acceptance test is: connect compliant and noncompliant test endpoints and inspect the different authorized access results.
D:This test measures a different behavior: Capture frames on the physical link and confirm encrypted MACsec data with authorized peers maintaining connectivity. It does not establish the target outcome. For the documented fault, the direct acceptance test is: connect compliant and noncompliant test endpoints and inspect the different authorized access results.
Question 748
Corporate endpoints connect to a trusted VLAN but unmanaged devices can join with no posture assessment or isolation. During troubleshooting: An unmanaged infected laptop obtains the same internal reachability as managed devices. Which underlying cause best explains the recorded behavior?
- Endpoint admission and posture enforcement are absent at access boundaries.
- The Ethernet hop lacks functioning MACsec encryption despite ordinary VLAN segmentation.
- Policy was tied only to IP/VLAN placement rather than the intended TrustSec identity tags.
- The transit path does not carry or reconstruct security group tags to the enforcement point.
Explanation
Correct Answer
A:The actual technical cause is: Endpoint admission and posture enforcement are absent at access boundaries. It specifically explains the observation: an unmanaged infected laptop obtains the same internal reachability as managed devices. The correcting configuration is: introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately.
Incorrect Answers
B:That diagnosis is supported by a different symptom: A passive tap reads sensitive unencrypted payloads on the supposedly protected switch-to-switch wire. Here the recorded observation is: an unmanaged infected laptop obtains the same internal reachability as managed devices. The applicable cause is: endpoint admission and posture enforcement are absent at access boundaries.
C:That diagnosis is supported by a different symptom: A user moved to a new VLAN bypasses the old subnet-based segmentation policy. Here the recorded observation is: an unmanaged infected laptop obtains the same internal reachability as managed devices. The applicable cause is: endpoint admission and posture enforcement are absent at access boundaries.
D:That diagnosis is supported by a different symptom: The destination SGACL treats all traffic as unknown SGT despite correct access-edge classification. Here the recorded observation is: an unmanaged infected laptop obtains the same internal reachability as managed devices. The applicable cause is: endpoint admission and posture enforcement are absent at access boundaries.
Question 749
Corporate endpoints connect to a trusted VLAN but unmanaged devices can join with no posture assessment or isolation. The initial change is: Introduce supported endpoint posture/security controls and isolate or restrict noncompliant endpoints appropriately. Which continuing control most directly prevents a recurrence of the documented problem: An unmanaged infected laptop obtains the same internal reachability as managed devices.
- Review SGT classification and SGACL matrix assignments as identity groups change.
- Manage MACsec keys/certificates and link compatibility during interface or optics changes.
- Retest posture and endpoint lifecycle controls when device agents or certificates change.
- Audit SGT propagation when traversing mixed-capability fabric and firewalls.
Explanation
Correct Answer
C:The continuing protective control is: Retest posture and endpoint lifecycle controls when device agents or certificates change. This addresses the underlying failure mechanism: endpoint admission and posture enforcement are absent at access boundaries. The corresponding operational check is: connect compliant and noncompliant test endpoints and inspect the different authorized access results.
Incorrect Answers
A:That control reduces a separate risk: Policy was tied only to IP/VLAN placement rather than the intended TrustSec identity tags. For the described design, the recurring risk arises from: endpoint admission and posture enforcement are absent at access boundaries. The specific required safeguard is: retest posture and endpoint lifecycle controls when device agents or certificates change.
B:That control reduces a separate risk: The Ethernet hop lacks functioning MACsec encryption despite ordinary VLAN segmentation. For the described design, the recurring risk arises from: endpoint admission and posture enforcement are absent at access boundaries. The specific required safeguard is: retest posture and endpoint lifecycle controls when device agents or certificates change.
D:That control reduces a separate risk: The transit path does not carry or reconstruct security group tags to the enforcement point. For the described design, the recurring risk arises from: endpoint admission and posture enforcement are absent at access boundaries. The specific required safeguard is: retest posture and endpoint lifecycle controls when device agents or certificates change.
Question 750
A data-center perimeter must identify and block application-specific threats on encrypted HTTPS traffic where policy authorizes inspection. The incident evidence is: A basic destination-port ACL permits both harmless and malicious traffic on TCP443. Which targeted configuration or design change best addresses the failure?
- Use Cisco TrustSec security group tags and SGACL enforcement where the platform and design support it.
- Use a suitable next-generation firewall with application awareness and permitted TLS inspection controls.
- Enable the supported SGT propagation or mapping mechanism across the relevant transit path.
- Use defense-in-depth controls such as segmented access, threat inspection and least-privilege policy at the relevant boundaries.
Explanation
Correct Answer
B:The required correction is: Use a suitable next-generation firewall with application awareness and permitted TLS inspection controls. The underlying failure mechanism is: Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context. Verify success by carrying out this direct test: test a known allowed business app and a blocked malicious signature in the approved inspection scope.
Incorrect Answers
A:Policy was tied only to IP/VLAN placement rather than the intended TrustSec identity tags. Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context.
C:The transit path does not carry or reconstruct security group tags to the enforcement point. Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context.
D:No internal segmentation or layered threat controls protect east-west movement. Port/protocol-only filtering cannot recognize application-layer signatures or allowed decryption context.
Implementing Cisco Enterprise Network Core Technologies (ENCOR) (350-401) Practice Tests