What is one of the techniques for mitigating VLAN attacks?

What is one of the techniques for mitigating VLAN attacks?

• A. Enable DTP
• B. Set the native VLAN to an unused VLAN
• C. Allow all VLANs to trunk
• D. Utilize a VLAN management protocol

Answer: (B)

Setting the native VLAN to an unused VLAN is an effective technique for mitigating VLAN attacks, particularly VLAN hopping. In a VLAN hopping attack, an attacker can send traffic from one VLAN to another by exploiting the native VLAN configuration. By configuring the native VLAN to a VLAN that is not actively used for legitimate traffic, you reduce the risk of this type of attack. When the native VLAN is set to an unused VLAN, any untagged frames sent by devices can be isolated from legitimate traffic, preventing unauthorized access and eavesdropping on other VLANs. This practice enhances the overall security of the network by ensuring that even if a device tries to exploit VLAN hopping, there is no vulnerable native VLAN for it to exploit. Options such as enabling Dynamic Trunking Protocol (DTP), allowing all VLANs on a trunk, or utilizing a VLAN management protocol do not directly help in mitigating VLAN attacks. In fact, enabling DTP may introduce vulnerabilities as it can dynamically negotiate trunking and create unintended trunk links, while allowing all VLANs can also widen the potential attack surface. Similarly, VLAN management protocols may assist in management but do not inherently secure the environment against VLAN attacks.

Setting the native VLAN to an unused VLAN is an effective technique for mitigating VLAN attacks, particularly VLAN hopping. In a VLAN hopping attack, an attacker can send traffic from one VLAN to another by exploiting the native VLAN configuration. By configuring the native VLAN to a VLAN that is not actively used for legitimate traffic, you reduce the risk of this type of attack.

When the native VLAN is set to an unused VLAN, any untagged frames sent by devices can be isolated from legitimate traffic, preventing unauthorized access and eavesdropping on other VLANs. This practice enhances the overall security of the network by ensuring that even if a device tries to exploit VLAN hopping, there is no vulnerable native VLAN for it to exploit.

Options such as enabling Dynamic Trunking Protocol (DTP), allowing all VLANs on a trunk, or utilizing a VLAN management protocol do not directly help in mitigating VLAN attacks. In fact, enabling DTP may introduce vulnerabilities as it can dynamically negotiate trunking and create unintended trunk links, while allowing all VLANs can also widen the potential attack surface. Similarly, VLAN management protocols may assist in management but do not inherently secure the environment against VLAN attacks.