Which configuration part specifies the traffic class for LLQ?
An engineer is configuring LLQ in a network and completes the section for identifying different DSCP markings. Which part of the configuration specifies the traffic class for LLQ?
Community Votes
80% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.
Community Insight
The exam tests the distinction between defining traffic (class-map) and applying actions like LLQ (policy-map). The common trap is confusing the classification step with the enforcement step.
This question tests the understanding of Cisco IOS Quality of Service (QoS) hierarchy, specifically how Low Latency Queuing (LLQ) is implemented. The community consensus and official documentation confirm that the policy map is where the LLQ priority command is applied to a defined class.
Option A (class map) is chosen by some candidates who correctly identify that class maps define traffic but mistakenly believe they also specify the LLQ action. However, class maps only match traffic; they do not configure queuing behavior.
Community Discussion (5 comments)
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Expert Analysis
Why the Answer Is Correct
In Cisco IOS QoS configuration, the Policy Map is the component where specific actions are assigned to traffic classes. To implement Low Latency Queuing (LLQ), you must use thepriority command within the policy map configuration mode. This command explicitly defines the traffic as belonging to the LLQ class, ensuring it receives strict priority queuing.Why the Other Options Are Wrong
A Class Map (Option A) is used solely to classify and match traffic based on criteria like DSCP or ACLs; it does not contain QoS actions like queuing. An Access List (Option D) is often used within a class map to match traffic but is not the structure that applies LLQ. A Service Policy (Option C) refers to the application of the policy map to an interface (service-policy output/policy-name), not the internal configuration of the LLQ parameters themselves.Community Comment Notes
Comment [1] provides the official Cisco documentation steps, confirming that thepolicy-map section includes the priority command required for LLQ. Comment [2] clearly outlines the three-step sequence: Class Map (define/match), Policy Map (apply behavior/LLQ), and Service Policy (apply to interface). Comment [3] argues for Option A, likely confusing the identification of the class with the specification of the LLQ mechanism, which is technically incorrect in the context of 'configuring LLQ'. Exam Strategy
Memorize the QoS workflow order: Match (Class Map) -> Action (Policy Map) -> Apply (Service Policy). When asked about 'configuring LLQ' or 'assigning priority', always look for the Policy Map, as this is where the priority keyword resides.