In this article we will mitigate VLAN hopping by switch spoofing in the way that we will disable trunking on the ports who do not have to become trunk ports. Some Cisco switches ports default to auto mode for trunking. That means that the ports automatically become trunk ports if they receive Dynamic Trunking Protocol (DTP) frames on some of the switch ports.
Tag: vlan hopping
VLAN hopping attack can be possible by two different approaches, Switch Spoofing or Double tagging.
When you are in a situation where you need to configure and set up security of VLAN trunks, also consider the potential for an exploit called VLAN hopping. Attacker can craft and send positioned frames on one access VLAN with spoofed 802.1Q tags so that the packet end up on a totally different VLAN and all this without the use of a router.