When a switch is improperly connected to a network, it can cause widespread connectivity issues, especially if there’s a misconfiguration in VLAN settings. A Native VLAN mismatch occurs when two switches connected via a trunk link have different native VLANs configured for untagged traffic. This can cause traffic to be sent to the wrong VLAN or dropped, resulting in connectivity loss for users.

Scenario Analysis: The intern likely connected the switch without ensuring that the trunk port’s native VLAN matched the existing network configuration. This is a common issue in Cisco-based networks when trunk links are misconfigured.

Why not VTP update? VLAN Trunking Protocol (VTP) updates propagate VLAN configurations across switches. While a VTP misconfiguration could cause issues, it’s less likely to immediately disrupt connectivity for many users unless the VTP server deleted critical VLANs, which is not implied here.

Why not Port security issue? Port security restricts access based on MAC addresses, typically affecting individual ports, not causing widespread outages.

Why not LLDP misconfiguration? Link Layer Discovery Protocol (LLDP) is used for device discovery, and misconfiguration is unlikely to cause a broad loss of connectivity.