A VoIP phone powers up, but it is unable to receive or place calls. After connecting to another switchport, the issue is resolved. Which of the following was most likely the issue with the previous…

The correct answer is C. The port had an incorrect VLAN assignment. The phone received power but was on the wrong VLAN, preventing it from reaching the voice‑VLAN DHCP/TFTP services needed to register and place calls.

Submitted by kim_seoul· Mar 6, 2026Network Troubleshooting

Question

A VoIP phone powers up, but it is unable to receive or place calls. After connecting to another switchport, the issue is resolved. Which of the following was most likely the issue with the previous port?

Options

AThe port had a half-duplex configuration.
BThe port was in an error-disabled state.
CThe port had an incorrect VLAN assignment.
DThe port exceeded its PoE budget.

How the community answered

(38 responses)

A
13% (5)
B
8% (3)
C
76% (29)
D
3% (1)

Explanation

The phone received power but was on the wrong VLAN, preventing it from reaching the voice‑VLAN DHCP/TFTP services needed to register and place calls.

Community Discussion

No community discussion yet for this question.

Full N10-009 Practice