200-301 Question 178
Single answerA network engineer is troubleshooting a newly installed switch and notices that devices connected to the switch cannot communicate. Upon investigation, the engineer finds that all ports are in VLAN 1. Which statement best describes the role of VLAN 1 in this situation?
- A
VLAN 1 is the default VLAN and is used for management traffic only.
- B
VLAN 1 is the default VLAN for all switch ports and user traffic unless explicitly assigned to another VLAN.
- C
VLAN 1 is disabled by default on modern Cisco switches.
- D
VLAN 1 cannot be used for user traffic and must be changed to another VLAN for communication.
Show answer and explanation
Correct answer: B
Explanation
By default, all switch ports on a Cisco switch are assigned to VLAN 1, which is the default VLAN for both user and management traffic. While VLAN 1 can carry traffic, it is often recommended to reassign ports to another VLAN for enhanced network segmentation and security. The scenario highlights this default behavior of VLAN 1.
- A. Incorrect.
VLAN 1 is not exclusively used for management traffic. While it can carry management traffic, by default it is also used for user traffic unless reassigned.
- B. Correct.
This is correct. VLAN 1 is the default VLAN assigned to all switch ports unless they are explicitly configured to another VLAN. It carries both management and user traffic by default.
- C. Incorrect.
This is incorrect. VLAN 1 is enabled by default on all Cisco switches and cannot be disabled.
- D. Incorrect.
This is incorrect. VLAN 1 can carry user traffic by default. It is best practice, however, to avoid using VLAN 1 for security reasons.