Which Protocols Can Detect Native VLAN Mismatch Errors?

AC

The correct answers for the question are: A. STP and C. Cisco Discovery Protocol.

Explanation:

A native VLAN mismatch occurs when two devices connected to the same trunk link have different native VLAN configurations. This can cause communication errors and security issues. To avoid this, two protocols can detect native VLAN mismatch errors:

1. Spanning Tree Protocol (STP): STP is a layer 2 protocol that provides loop prevention in switched networks. It can detect native VLAN mismatches by monitoring the BPDU (Bridge Protocol Data Unit) sent between switches. If two switches have different native VLAN configurations, the BPDU will contain different information, and STP will detect the mismatch.

2. Cisco Discovery Protocol (CDP): CDP is a proprietary layer 2 protocol developed by Cisco that provides device discovery and information. It can detect native VLAN mismatches by comparing the native VLAN information advertised by neighboring devices. If two devices have different native VLAN configurations, CDP will report a native VLAN mismatch.

The other options are not capable of detecting native VLAN mismatches:

• PAgP (Port Aggregation Protocol) is used for link aggregation and does not deal with VLANs.
• DTP (Dynamic Trunking Protocol) is used for automatic trunk configuration and negotiation, but does not verify native VLAN configurations.
• VTP (VLAN Trunking Protocol) is used for VLAN management and propagation, but does not directly verify native VLAN configurations.