Cisco
400-007 · Question #56
400-007 Question #56: Real Exam Question with Answer & Explanation
The correct answer is C: IPv6 and IB/4 traffic types can use a single QoS policy to match both protocols. When deploying QoS in a dual-stack IPv4/IPv6 network, Cisco MQC allows a single service policy to classify and manage traffic from both protocol families simultaneously.
Question
You are designing a network running both IPv4 and IPv6 to deploy QoS. Which consideration is correct about the QoS for IPv4 and IPv6?
Options
- AIPv4 and IPv6 traffic types can use use queuing mechanisms such as LLQ, PQ and CQ.
- BIPv6 packet classification is only available with process switching, whereas IPv4 packet
- CIPv6 and IB/4 traffic types can use a single QoS policy to match both protocols
- DDifferent congestion management mechanisms need to be used for IPv4 and IPv6 traffic types
Explanation
When deploying QoS in a dual-stack IPv4/IPv6 network, Cisco MQC allows a single service policy to classify and manage traffic from both protocol families simultaneously.
Common mistakes.
- A. PQ (Priority Queuing) and CQ (Custom Queuing) are legacy IOS interface-level queuing mechanisms that have largely been superseded by MQC-based tools, and claiming they apply equivalently to IPv6 in modern dual-stack deployments is inaccurate.
- B. IPv6 packet classification fully supports Cisco Express Forwarding (CEF) switching, so restricting it to process switching only is factually incorrect and would represent a severe performance limitation that does not exist in modern IOS.
- D. The same congestion management mechanisms such as CBWFQ and LLQ apply equally to IPv4 and IPv6 traffic within a single MQC policy, so requiring different mechanisms per protocol type is incorrect.
Concept tested. Dual-stack QoS single MQC policy support
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