Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
Exhibit
show interfaces status Gi1/0/10 connected 20 a-full a-100 10/100/1000BaseTX show vlan brief 10 Users active 30 Voice active 20 inactive
Exhibit: A PC connected to SW1 cannot reach the default gateway. The access port is assigned to VLAN 20, but the switch output below is shown. What is the most likely cause?
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
Distractor review
Port security has shut down the interface
The interface is shown as connected, not secure-shutdown.
B
Best answer
VLAN 20 does not exist or is not active on the switch
That is exactly what the inactive VLAN status is telling you.
C
Distractor review
The port must be converted to a trunk
A normal user PC should stay on an access port.
D
Distractor review
The default gateway must be configured on the physical switch port
Default gateways are not configured on switch access ports.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is to assume that because the access port is operationally up, the VLAN assignment is correct and active. Candidates often overlook verifying whether VLAN 20 actually exists or is active on the switch. This leads to selecting incorrect answers like port security shutdown or trunk configuration, which do not explain the inactive VLAN status. The trap is confusing physical link status with VLAN operational status, which are independent in Cisco switches.
Technical deep dive
How to think about this question
Virtual LANs (VLANs) segment a physical switch into multiple logical broadcast domains, allowing devices on the same VLAN to communicate directly. Each VLAN must be explicitly created and active in the switch's VLAN database for ports assigned to that VLAN to forward traffic correctly. When a port is configured as an access port, it tags all incoming traffic with the assigned VLAN ID internally and forwards it only to ports within the same VLAN. If a VLAN assigned to an access port does not exist or is inactive, the switch cannot forward traffic for that VLAN. The port may show as operationally up because the physical link is active, but the VLAN inactivity prevents any Layer 2 forwarding for that VLAN. This causes devices connected to that port to lose connectivity to other VLAN members and the default gateway, which is typically configured on a Layer 3 interface or switch virtual interface (SVI) for that VLAN. The exam trap here is assuming that a port being up means the VLAN is correctly configured and active. In reality, an access port assigned to a non-existent VLAN will not forward traffic, causing connectivity issues. Practically, network engineers must verify VLAN creation and status using commands like 'show vlan brief' to ensure the VLAN is active and properly assigned to the port, avoiding this common misconfiguration.
KKey Concepts to Remember
- A VLAN must exist and be active in the VLAN database for an access port assigned to that VLAN to forward user traffic correctly.
- An access port configured with a VLAN that is inactive or missing will not carry normal user traffic, causing connectivity failures to devices like default gateways.
- Switch ports assigned to access VLANs do not require trunk configuration unless they need to carry multiple VLANs simultaneously.
- Default gateways are configured on Layer 3 devices or switch SVIs, not on physical Layer 2 access ports.
- The operational status of a switch port being up does not guarantee that the VLAN assigned to it is active or valid.
- Inactive VLANs appear in the VLAN database but are not operational, which prevents any traffic tagged or assigned to them from passing through the switch.
- Switches use the VLAN database to determine which VLANs are valid and active, and ports assigned to non-existent VLANs will not forward traffic properly.
- Troubleshooting VLAN connectivity issues requires verifying VLAN existence and status on the switch, especially when access ports cannot reach the default gateway.
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 VLAN must exist and be active in the VLAN database for an access port assigned to that VLAN to forward user traffic correctly.
What is the correct answer to this question?
The correct answer is: VLAN 20 does not exist or is not active on the switch — The port is operationally up, but VLAN 20 is listed as inactive because that VLAN does not exist in the VLAN database. An access port assigned to a missing VLAN will not carry normal user traffic for that VLAN.
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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