Trunk Link Attacks on CompTIA Network+ N10-007 Exam

An attacker has inserted a hub into a trunk link on the local network in an attempt to access the management subnet to attack the networking devices.

Which of the following attacks can be used on a trunk link to provide access to the management subnet?

A.

Brute force

B.

VLAN hopping

C.

Evil twin

D.

DNS poisoning.

B.

In this scenario, the attacker has inserted a hub into a trunk link on the local network, which means they are attempting to access the management subnet to attack networking devices. To accomplish this, the attacker may use a variety of attacks. Of the options listed, the most likely attack to be used on a trunk link to gain access to the management subnet is VLAN hopping (Option B).

VLAN hopping is a type of attack that takes advantage of a misconfigured switch. The attack works by tricking the switch into forwarding traffic from one VLAN to another, allowing an attacker to access a VLAN they are not authorized to be on. In a trunk link scenario, an attacker can use VLAN hopping to gain access to the management VLAN, which is often used to manage networking devices such as switches and routers.

In a VLAN hopping attack, the attacker creates a fake or "spoofed" frame that appears to come from a trusted device on one VLAN, but is actually intended for a device on another VLAN. The attacker then sends this frame to the switch via the trunk link, and the switch forwards the frame to the intended VLAN. This allows the attacker to access the target VLAN and potentially compromise devices on that network.

It's important to note that VLAN hopping requires a misconfigured switch, so proper configuration and monitoring of network devices can help prevent this type of attack. Additionally, using encryption protocols like SSH or HTTPS to manage network devices can help protect against unauthorized access to the management VLAN.