Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A switch port should allow an IP phone and attached PC to operate correctly. The phone should place voice traffic in VLAN 200 while the PC remains in VLAN 20. Which configuration approach 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
Configure the port with an access VLAN for data and a voice VLAN for the phone
This is correct because Cisco voice-VLAN design allows user data and tagged voice traffic to coexist correctly on one edge port.
B
Distractor review
Configure the port as a routed port with no switchport
This is wrong because an end-user phone/PC port is not a routed-port design case.
C
Distractor review
Configure the port as an EtherChannel member
This is wrong because EtherChannel bundles links and is unrelated to one phone-plus-PC edge connection.
D
Distractor review
Use a native VLAN only and disable all tagging
This is wrong because the design explicitly calls for distinct voice and data VLAN treatment.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is selecting a trunk port configuration or routed port for an IP phone and PC connection. Trunk ports tag all VLAN traffic and are designed for switch-to-switch links, not edge devices. Routed ports disable switching and cannot carry multiple VLANs or support downstream devices. Another trap is disabling tagging entirely and relying on a native VLAN only, which fails to separate voice and data traffic as required. Understanding that Cisco’s voice VLAN feature allows a single access port to handle untagged data and tagged voice traffic simultaneously is critical to avoid these mistakes.
Technical deep dive
How to think about this question
In Cisco networking, a switch port that connects both an IP phone and a PC must handle two types of traffic: voice and data. The IP phone typically tags its voice traffic with a specific VLAN ID (voice VLAN), while the PC sends untagged data traffic assigned to an access VLAN. Cisco switches support this design by allowing a single physical port to carry untagged data frames for the PC and tagged voice frames from the phone, keeping traffic logically separated without requiring multiple physical connections. The configuration involves setting the switch port as an access port assigned to the data VLAN (VLAN 20 in this case) and enabling a voice VLAN (VLAN 200) on the same port. The voice VLAN feature instructs the switch to accept tagged frames from the IP phone on VLAN 200 while forwarding untagged frames from the PC on VLAN 20. This approach ensures proper QoS treatment for voice traffic and maintains network segmentation between voice and data. A common exam trap is confusing this setup with trunk ports or routed ports. Trunk ports carry multiple VLANs tagged on all frames, which is unnecessary and less secure for edge ports with IP phones. Routed ports disable switching and are unsuitable for end devices. The voice VLAN feature is a Cisco-specific enhancement designed to simplify IP phone deployments and avoid the complexity of multiple physical ports or manual VLAN tagging on PCs.
KKey Concepts to Remember
- A Cisco switch port configured with an access VLAN forwards untagged data frames from connected PCs in that VLAN.
- The voice VLAN feature allows a switch port to accept tagged voice traffic from IP phones on a separate VLAN while maintaining untagged data traffic on the access VLAN.
- Cisco IP phones tag their voice traffic with the configured voice VLAN ID, enabling QoS and traffic separation on a single physical port.
- A switch port configured as a routed port disables switching functions and cannot support multiple VLANs or downstream devices like IP phones and PCs.
- EtherChannel bundles multiple physical links into one logical link and is unrelated to single-port IP phone and PC connections.
- Native VLANs carry untagged traffic on trunk ports but do not support the separation of voice and data VLANs on a single access port.
- The voice VLAN feature simplifies network design by allowing logical separation of voice and data traffic without requiring multiple physical ports or complex trunking.
- Proper VLAN configuration on IP phone ports ensures voice traffic receives priority and security distinct from user data traffic.
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.
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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 Cisco switch port configured with an access VLAN forwards untagged data frames from connected PCs in that VLAN.
What is the correct answer to this question?
The correct answer is: Configure the port with an access VLAN for data and a voice VLAN for the phone — The best approach is to configure the access VLAN for user data and the voice VLAN separately. In plain language, the PC should remain a normal untagged data endpoint in VLAN 20, while the phone can tag its own voice traffic for VLAN 200. Cisco access-port designs support this exact use case and allow the switch to keep voice and user traffic logically separated without requiring two physical ports. This is a classic CCNA edge-port design. It is not a general trunking problem, and it does not require EtherChannel or router subinterfaces. The important idea is that one switchport can support an access VLAN and a voice VLAN together in a way designed specifically for IP phones with downstream PCs.
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.
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