hardMultiple Choice
350-401 Practice Question: Runs the following command on Router R9: R9# show…
A network engineer runs the following command on Router R9:
R9# show queueing interface GigabitEthernet0/1 Interface GigabitEthernet0/1 queueing strategy: class-based weighted fair
Queueing on output: Class-based Weighted Fair Queueing Queueing on input: FIFO
R9# show policy-map interface GigabitEthernet0/1
GigabitEthernet0/1
Service-policy output: QOS_POLICY
Class-map: VOICE (match-any) 100 packets, 10000 bytes 5 minute offered rate 10000 bps, drop rate 0 bps Match: ip dscp ef (46) Queueing strict priority queue limit 64 packets (queue depth/total drops/no-buffer drops) 0/0/0 (pkts output/bytes output) 100/10000 police cir 1000000 bc 15625 be 15625 conformed 100 packets, 10000 bytes; actions: transmit exceeded 0 packets, 0 bytes; actions: drop violated 0 packets, 0 bytes; actions: drop
Class-map: DATA (match-any) 200 packets, 20000 bytes 5 minute offered rate 20000 bps, drop rate 0 bps Match: ip dscp af31 (26) Queueing (queue depth/total drops/no-buffer drops) 0/0/0 (pkts output/bytes output) 200/20000 bandwidth remaining percent 50
Class-map: class-default (match-any) 300 packets, 30000 bytes 5 minute offered rate 30000 bps, drop rate 0 bps Match: any Queueing (queue depth/total drops/no-buffer drops) 0/0/0 (pkts output/bytes output) 300/30000 bandwidth remaining percent 50
Based on this output, what can be concluded?
⚠ Common exam trap
Cisco often tests the distinction between 'bandwidth percent' (which allocates a percentage of the total interface bandwidth) and 'bandwidth remaining percent' (which allocates a percentage of the bandwidth left after priority queuing), and candidates frequently confuse these two commands.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Data traffic is guaranteed 50% of the remaining bandwidth after priority queuing.
The 'bandwidth remaining percent 50' command under the DATA class-map allocates 50% of the interface bandwidth that remains after the strict-priority VOICE queue has been serviced. This is the standard behavior for class-based weighted fair queuing (CBWFQ) when a priority queue is present: the priority queue is served first, and then the remaining bandwidth is distributed among the non-priority classes according to their configured percentages.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The interface uses WFQ for output queuing.
Why it's wrong here
The output explicitly identifies 'class-based weighted fair', which is CBWFQ, not legacy WFQ. WFQ automatically classifies traffic by flows and IP precedence, while CBWFQ creates explicit user-defined classes with dedicated bandwidth guarantees. Since this policy-map defines VOICE and DATA classes with custom queueing parameters, the scheduler is CBWFQ, not WFQ.
- ✗
Voice traffic is being dropped because it exceeds the police rate.
Why it's wrong here
The police configuration in the VOICE class has a conform-action of transmit, and interface counters show only conformed packets with zero exceeded packets, proving no voice packets are being dropped. The police rate is set high enough to carry the actual voice traffic volume, so every packet stays within the committed burst and the exceed-action is never triggered. Thus, the premise that voice exceeds the police rate is false.
- ✓
Data traffic is guaranteed 50% of the remaining bandwidth after priority queuing.
Why this is correct
The DATA class is configured with 'bandwidth remaining percent 50', meaning it is guaranteed 50% of the bandwidth left after the strict priority queue (LLQ) for VOICE has been served. This is relative to remaining bandwidth, not a fixed absolute percentage of the interface rate, so data can use more than half when voice is silent but is protected to at least half when voice is active. It is a correct statement about the policy's bandwidth allocation.
- ✗
The policy-map is applied to input traffic.
Why it's wrong here
The output states 'Service-policy output', confirming that the policy-map is attached to the output direction of the interface. An input service policy would display 'Service-policy input' and would be used for ingress classification, marking, or policing, not for transmit-side queueing. Because this policy contains queueing actions such as priority and bandwidth, applying it in the input direction would be invalid; it must be output to affect the transmit queue.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-401 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-401 exam.