The solution is to disable auto trunking and
move native VLANs to unused VLANs.
VLAN hopping is a PC security misuse, a strategy for
assaulting networked assets on a virtual LAN (VLAN). The fundamental idea
driving all VLAN hopping assaults is for an assaulting host on a VLAN to access
traffic on different VLANs that would ordinarily not be accessible.