Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A switch port connected to an IP phone and a PC should separate voice traffic from data traffic while still using one physical edge connection. Which feature best supports that design?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
Voice VLAN
This is correct because a voice VLAN separates phone traffic from user data on a shared edge port.
B
Distractor review
EtherChannel
This is wrong because EtherChannel bundles links and does not solve this voice/data separation problem.
C
Distractor review
Native VLAN
This is wrong because native VLAN is a trunking concept, not the endpoint voice/data separation feature described.
D
Distractor review
Loop guard
This is wrong because loop guard is an STP protection feature.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is selecting Native VLAN as the answer because it involves VLAN tagging and trunk ports, which might seem related to traffic separation. However, native VLAN applies only to trunk links between switches and does not separate voice and data traffic on a single access port. Another tempting but incorrect choice is EtherChannel, which aggregates multiple links for bandwidth but does not segregate traffic types. Confusing loop guard with voice VLAN is also a trap, as loop guard protects against Layer 2 loops and is unrelated to traffic separation. Understanding that voice VLAN specifically isolates voice traffic on a single port is key to avoiding these traps.
Technical deep dive
How to think about this question
A voice VLAN is a specialized VLAN configured on a switch port to separate voice traffic from regular data traffic when both share the same physical connection. This feature is essential in environments where an IP phone and a PC connect to the same switch port, allowing the switch to tag voice packets with a dedicated VLAN ID. This separation ensures that voice traffic receives appropriate Quality of Service (QoS) treatment and security, preventing interference with data traffic and optimizing voice call quality. When configuring a voice VLAN on a Cisco switch, the port operates in access mode for the data VLAN and simultaneously supports a voice VLAN for the IP phone. The switch recognizes voice traffic by the phone’s VLAN tagging or by the phone’s CDP (Cisco Discovery Protocol) information, enabling the switch to forward voice frames on the voice VLAN while forwarding PC data frames on the data VLAN. This dual VLAN handling on a single physical port is crucial for enterprise edge designs where minimizing cabling and switch port usage is a priority. A common exam trap is confusing the voice VLAN feature with trunking concepts like native VLAN or link aggregation technologies such as EtherChannel. Voice VLAN is not about trunking between switches but about segregating traffic types on one access port. Practically, voice VLANs improve network performance and security by isolating voice traffic, which is sensitive to latency and jitter, from regular data traffic, ensuring reliable IP telephony services.
KKey Concepts to Remember
- A voice VLAN separates IP phone voice traffic from PC data traffic on the same physical switch port to ensure traffic segregation and QoS.
- Cisco switches use voice VLAN configuration to tag and forward voice packets on a dedicated VLAN while forwarding PC data on the native access VLAN.
- Voice VLANs enable a single switch port to support both voice and data traffic without requiring multiple physical connections or trunk ports.
- The switch detects IP phones via Cisco Discovery Protocol (CDP) or VLAN tagging to apply the voice VLAN configuration dynamically.
- Native VLAN is a trunking concept that does not separate voice and data traffic on a single access port and is not suitable for voice VLAN scenarios.
- EtherChannel bundles multiple physical links into one logical link and does not address traffic separation between voice and data on a single port.
- Loop guard is a Spanning Tree Protocol (STP) feature that prevents loops and does not relate to voice and data traffic separation on switch ports.
- Voice VLANs improve voice quality by isolating voice traffic, allowing network administrators to apply QoS policies specific to voice VLANs.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
CCNA DHCP practice questions
Practise DHCP scopes, relay, leases and troubleshooting.
CCNA show ip route practice questions
Practise routing-table output, longest-prefix match, AD and route selection.
CCNA show interfaces trunk practice questions
Practise trunk verification and VLAN forwarding across switches.
CCNA wireless security practice questions
Practise WLAN security, authentication and wireless architecture concepts.
CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
A voice VLAN separates IP phone voice traffic from PC data traffic on the same physical switch port to ensure traffic segregation and QoS.
What is the correct answer to this question?
The correct answer is: Voice VLAN — A voice VLAN best supports that design. In practical terms, a Cisco-style voice VLAN allows the switch to carry voice traffic separately from user data even though the phone and PC share the same physical access connection. This is a common enterprise edge design because it lets the phone use one VLAN while the downstream PC uses another. The key point is separation of traffic types over one edge port, not trunking between switches or link aggregation.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
Loading comments…
Sign in to join the discussion.