Question

Difficulty: EasyTroubleshooting VLAN, Trunking, and Switching Issues

A network technician plugs a newly deployed workstation into switch port GigabitEthernet0/12. The host successfully obtains an IP address in the default management network (192.168.1.0/24) and can reach local hosts in that same network, but it is unable to access any resources on the Finance subnet (192.168.30.0/24). An inspection reveals that the switch port is still using its factory default configuration. Which of the following is the most likely cause of this connectivity issue?

  1. The switch port is assigned to the default VLAN 1 rather than the designated Finance VLAN.Answer
  2. B
    Hosts residing on the same VLAN require an intermediate Layer 3 device to communicate with each other.
  3. C
    An 802.1Q native VLAN mismatch exists between the workstation's network card and the access switch port.
  4. D
    The switch port has auto-negotiated a full-duplex mismatch with the connected workstation interface.

Answer

The switch port is assigned to the default VLAN 1 rather than the designated Finance VLAN.
When a managed switch port remains in its default factory configuration, it is assigned to VLAN 1 (the default VLAN). As a result, any host connected to that port will reside in the VLAN 1 broadcast domain rather than the intended VLAN (such as VLAN 30 for Finance). To resolve the issue, the administrator must configure the interface as an access port and assign it to VLAN 30.

Step-by-Step Solution

1
Analyze the observed IP addressing and port configuration status.
The host received an IP address in the default network (192.168.1.0/24) corresponding to VLAN 1 because the unconfigured switch port defaults to VLAN 1.
Unconfigured Ethernet ports on a managed switch belong to the default broadcast domain (VLAN 1).
2
Determine why the host cannot reach the Finance subnet (192.168.30.0/24).
Because the host port is in VLAN 1, it cannot reach VLAN 30 resources without proper port VLAN reassignment and routing.
VLANs isolate broadcast domains at Layer 2.

Key Concept

Default Access Port VLAN Assignment
Rate this question