CompTIA Network+ Practice Test

What is the purpose of switch spoofing in a network attack?

1. To impersonate a legitimate network user

2. To negotiate a trunk link and break out of a VLAN

3. To disrupt Spanning Tree Protocol operations

4. To flood a switch with MAC addresses

The correct answer is: To negotiate a trunk link and break out of a VLAN

The correct answer highlights that switch spoofing primarily involves negotiating a trunk link to escape from a VLAN. In a typical network configuration, switches can separate broadcast domains using VLANs. When a switch is tricked into believing it should establish a trunk link, it may inadvertently allow traffic from multiple VLANs to flow across it. This can lead to unauthorized access to devices and data within those VLANs, effectively breaking the segregation that VLANs are meant to enforce. By manipulating the configuration negotiation process—specifically, the Dynamic Trunking Protocol (DTP)—an attacker can exploit this vulnerability. Once the trunk link is established, the attacker’s device can communicate with devices on various VLANs, potentially accessing sensitive information or disrupting normal network operations. In other contexts, impersonating a legitimate user focuses more on identity theft or gaining unauthorized access, while disrupting Spanning Tree Protocol operations usually involves creating network loops rather than necessarily gaining access to additional VLANs. Flooding a switch with MAC addresses primarily aims to overwhelm the switch's resources but does not directly involve manipulating VLAN configurations or trunking negotiations.