Question 470 BGP flaps during a burst of management traffic while hardware forwarding is healthy; a CoPP class policing all control traffic at one low rate is dropping BGP packets. Which technical mechanism best explains the behavior observed in this scenario? Unrestricted broad CoPP rate increases can remove protection of the router CPU while masking a classifier error. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. IPv4-only classifier syntax may not cover IPv6 packets even when the application protocol is the same. A CoPP class not matching SNMP can force it into default policing even when transport reachability and credentials are valid. ExplanationCorrect Answer B:CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. This explains why the initial condition produces the observed failure. The direct repair is: Separate critical routing protocols into correctly classified control-plane classes with justified policing rates. Validate through: Inspect CoPP class drop counters correlated with BGP session resets under controlled load. Other Answers A:Unrestricted broad CoPP rate increases can remove protection of the router CPU while masking a classifier error. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. C:IPv4-only classifier syntax may not cover IPv6 packets even when the application protocol is the same. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. D:A CoPP class not matching SNMP can force it into default policing even when transport reachability and credentials are valid. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic.
Question 471 BGP flaps during a burst of management traffic while hardware forwarding is healthy; a CoPP class policing all control traffic at one low rate is dropping BGP packets. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Verify SSH-class counters and a successful authenticated session at representative load. Under controlled load, verify SSH availability and stable CPU with other classes still dropping excess packets. Inspect CoPP class drop counters correlated with BGP session resets under controlled load. Compare CPU-punted control traffic counters with interface QoS counters for the transit stream. ExplanationCorrect Answer C:Inspect CoPP class drop counters correlated with BGP session resets under controlled load. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. Other Answers A:Verify SSH-class counters and a successful authenticated session at representative load. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. B:Under controlled load, verify SSH availability and stable CPU with other classes still dropping excess packets. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. D:Compare CPU-punted control traffic counters with interface QoS counters for the transit stream. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic.
Question 472 BGP flaps during a burst of management traffic while hardware forwarding is healthy; a CoPP class policing all control traffic at one low rate is dropping BGP packets. Which lasting design or operational safeguard best prevents this particular issue from recurring? Review actual control-plane encapsulations before writing class-map ACLs. Separate data-plane QoS objectives from device control-plane protection requirements. Build parallel IPv4/IPv6 CoPP coverage tests for dual-stack routing. Use per-protocol control-plane classification and baselined rate headroom. ExplanationCorrect Answer D:Use per-protocol control-plane classification and baselined rate headroom. This addresses the recurring cause: CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. A targeted acceptance check is: Inspect CoPP class drop counters correlated with BGP session resets under controlled load. Other Answers A:Review actual control-plane encapsulations before writing class-map ACLs. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. B:Separate data-plane QoS objectives from device control-plane protection requirements. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. C:Build parallel IPv4/IPv6 CoPP coverage tests for dual-stack routing. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic.
Question 473 SSH to a router fails during an incident, but the interface ACL explicitly permits port 22 and CoPP counters show SSH packets dropped. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Adjust the appropriate management CoPP class or rate rather than widening the interface ACL. Move data-plane rate controls to the appropriate interface QoS mechanism instead of treating CoPP as transit QoS. Add or adjust the SNMP management-plane classifier and rate for actual polling volume. Add correct IPv6 control-plane classification and rates for the intended BGP peers. ExplanationCorrect Answer A:Adjust the appropriate management CoPP class or rate rather than widening the interface ACL. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. Verify SSH-class counters and a successful authenticated session at representative load. Other Answers B:Move data-plane rate controls to the appropriate interface QoS mechanism instead of treating CoPP as transit QoS. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. C:Add or adjust the SNMP management-plane classifier and rate for actual polling volume. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. D:Add correct IPv6 control-plane classification and rates for the intended BGP peers. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them.
Question 474 SSH to a router fails during an incident, but the interface ACL explicitly permits port 22 and CoPP counters show SSH packets dropped. Which technical mechanism best explains the behavior observed in this scenario? CoPP governs traffic destined or punted to the router control plane, not ordinary hardware-switched forwarding. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. Defined class-maps and policy-maps do not police traffic until attached at the correct control-plane scope. CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. ExplanationCorrect Answer B:Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. This explains why the initial condition produces the observed failure. The direct repair is: Adjust the appropriate management CoPP class or rate rather than widening the interface ACL. Validate through: Verify SSH-class counters and a successful authenticated session at representative load. Other Answers A:CoPP governs traffic destined or punted to the router control plane, not ordinary hardware-switched forwarding. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. C:Defined class-maps and policy-maps do not police traffic until attached at the correct control-plane scope. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. D:CoPP can limit packets punted to the CPU; an overbroad class can starve essential routing control traffic. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them.
Question 475 SSH to a router fails during an incident, but the interface ACL explicitly permits port 22 and CoPP counters show SSH packets dropped. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. Compare CPU-punted control traffic counters with interface QoS counters for the transit stream. Verify SSH-class counters and a successful authenticated session at representative load. Under controlled load, verify SSH availability and stable CPU with other classes still dropping excess packets. ExplanationCorrect Answer C:Verify SSH-class counters and a successful authenticated session at representative load. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. Other Answers A:Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. B:Compare CPU-punted control traffic counters with interface QoS counters for the transit stream. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. D:Under controlled load, verify SSH availability and stable CPU with other classes still dropping excess packets. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them.
Question 476 SSH to a router fails during an incident, but the interface ACL explicitly permits port 22 and CoPP counters show SSH packets dropped. Which lasting design or operational safeguard best prevents this particular issue from recurring? Apply class-specific change limits and control-plane capacity acceptance tests. Audit control-plane service-policy attachments after template pushes. Build parallel IPv4/IPv6 CoPP coverage tests for dual-stack routing. Include management-plane traffic in CoPP stress tests and change reviews. ExplanationCorrect Answer D:Include management-plane traffic in CoPP stress tests and change reviews. This addresses the recurring cause: Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. A targeted acceptance check is: Verify SSH-class counters and a successful authenticated session at representative load. Other Answers A:Apply class-specific change limits and control-plane capacity acceptance tests. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. B:Audit control-plane service-policy attachments after template pushes. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. C:Build parallel IPv4/IPv6 CoPP coverage tests for dual-stack routing. Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them.
Question 477 A CoPP ACL classifies OSPF packets using only TCP or UDP ports, so OSPF control packets are never matched. Which corrective action most directly resolves the documented failure without suppressing unrelated safeguards? Match OSPF's actual IP protocol type and validate the applied class-map and policy-map. Adjust the appropriate management CoPP class or rate rather than widening the interface ACL. Separate critical routing protocols into correctly classified control-plane classes with justified policing rates. Move data-plane rate controls to the appropriate interface QoS mechanism instead of treating CoPP as transit QoS. ExplanationCorrect Answer A:Match OSPF's actual IP protocol type and validate the applied class-map and policy-map. OSPF uses its own IP protocol number rather than a TCP/UDP application port. Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. Other Answers B:Adjust the appropriate management CoPP class or rate rather than widening the interface ACL. OSPF uses its own IP protocol number rather than a TCP/UDP application port. C:Separate critical routing protocols into correctly classified control-plane classes with justified policing rates. OSPF uses its own IP protocol number rather than a TCP/UDP application port. D:Move data-plane rate controls to the appropriate interface QoS mechanism instead of treating CoPP as transit QoS. OSPF uses its own IP protocol number rather than a TCP/UDP application port.
Question 478 A CoPP ACL classifies OSPF packets using only TCP or UDP ports, so OSPF control packets are never matched. Which technical mechanism best explains the behavior observed in this scenario? Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. OSPF uses its own IP protocol number rather than a TCP/UDP application port. Defined class-maps and policy-maps do not police traffic until attached at the correct control-plane scope. IPv4-only classifier syntax may not cover IPv6 packets even when the application protocol is the same. ExplanationCorrect Answer B:OSPF uses its own IP protocol number rather than a TCP/UDP application port. This explains why the initial condition produces the observed failure. The direct repair is: Match OSPF's actual IP protocol type and validate the applied class-map and policy-map. Validate through: Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. Other Answers A:Control-plane policing can discard packets destined for the router after interface forwarding/ACL decisions permit them. OSPF uses its own IP protocol number rather than a TCP/UDP application port. C:Defined class-maps and policy-maps do not police traffic until attached at the correct control-plane scope. OSPF uses its own IP protocol number rather than a TCP/UDP application port. D:IPv4-only classifier syntax may not cover IPv6 packets even when the application protocol is the same. OSPF uses its own IP protocol number rather than a TCP/UDP application port.
Question 479 A CoPP ACL classifies OSPF packets using only TCP or UDP ports, so OSPF control packets are never matched. After applying the correction, which verification evidence most directly demonstrates that this issue is resolved? Compare CPU-punted control traffic counters with interface QoS counters for the transit stream. Send safe SSH connection attempts and verify the intended class's counters increment. Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. Inspect IPv6 BGP packet hits and neighbor health in the correct CoPP class. ExplanationCorrect Answer C:Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. This checks the affected traffic or control-plane behavior, not merely a generic up/down indicator. The underlying mechanism is: OSPF uses its own IP protocol number rather than a TCP/UDP application port. Other Answers A:Compare CPU-punted control traffic counters with interface QoS counters for the transit stream. OSPF uses its own IP protocol number rather than a TCP/UDP application port. B:Send safe SSH connection attempts and verify the intended class's counters increment. OSPF uses its own IP protocol number rather than a TCP/UDP application port. D:Inspect IPv6 BGP packet hits and neighbor health in the correct CoPP class. OSPF uses its own IP protocol number rather than a TCP/UDP application port.
Question 480 A CoPP ACL classifies OSPF packets using only TCP or UDP ports, so OSPF control packets are never matched. Which lasting design or operational safeguard best prevents this particular issue from recurring? Separate data-plane QoS objectives from device control-plane protection requirements. Build parallel IPv4/IPv6 CoPP coverage tests for dual-stack routing. Include management-plane traffic in CoPP stress tests and change reviews. Review actual control-plane encapsulations before writing class-map ACLs. ExplanationCorrect Answer D:Review actual control-plane encapsulations before writing class-map ACLs. This addresses the recurring cause: OSPF uses its own IP protocol number rather than a TCP/UDP application port. A targeted acceptance check is: Show OSPF hits in the intended CoPP class and stable neighbor state under a safe test. Other Answers A:Separate data-plane QoS objectives from device control-plane protection requirements. OSPF uses its own IP protocol number rather than a TCP/UDP application port. B:Build parallel IPv4/IPv6 CoPP coverage tests for dual-stack routing. OSPF uses its own IP protocol number rather than a TCP/UDP application port. C:Include management-plane traffic in CoPP stress tests and change reviews. OSPF uses its own IP protocol number rather than a TCP/UDP application port.
