CompTIA PenTest+ Practice Test

What is one of the most common methods of VLAN hopping?

1. Sending spoofed packets

2. Overflowing the MAC table

3. Creating a trunk link

4. Scanning for VLANs

The correct answer is: Overflowing the MAC table

One of the most common methods of VLAN hopping involves creating a trunk link. This method exploits the way switches handle VLANs and trunking protocols. When a switch port is configured as a trunk, it can carry traffic for multiple VLANs simultaneously. An attacker can configure their device to masquerade as a trunk port, effectively allowing it to bypass the normal VLAN segregation designed to keep traffic from different VLANs isolated. This can lead to the attacker gaining access to multicast and broadcast traffic sent to other VLANs or even to sensitive information that is not intended for the attacker's VLAN. By improperly setting up a trunk link, an attacker can gain unauthorized access to different segments of the network, allowing for potential data interception and manipulation. In contrast, other methods such as sending spoofed packets or overflowing the MAC table focus on different vulnerabilities or attack vectors but do not specifically exploit VLAN trunking. Scanning for VLANs is also important for reconnaissance but does not actively facilitate VLAN hopping the way creating a trunk link does.