We will discuss a basic VLAN hopping attack that uses a rogue trunk link, as shown in Figure 8-4. In this attack, the attcker takes advantage of the default automatic trunking configuration found on most switches. The attacker first gets access to a vacant port on a switch and then configures a system, most likely a laptop computer, present itself as a switch. It is possible to do so if the system is fitted with an 802.1Q or ISL capable NIC, using appropriate software that usually comes with the NIC itself.