When trying to add a now access switch to the network, theswitch port at the...

The issue involves a new access switch’s port being automatically disabled when connected to an aggregation switch, likely due to a Spanning Tree Protocol (STP) protection mechanism.

Analysis of Options:

Option A (Disable bpdu-filter):BPDU filtering prevents BPDUs from being sent or processed, which could cause loops, not resolve the issue.

Option B (Disable root-guard):Root guard prevents a port from becoming the root bridge but does not cause port disablement in this context.

Option C (Disable loop-guard):Loop guard prevents alternate ports from becoming designated but is unrelated to port disablement.

Option D:Correct. Disabling BPDU guard on the aggregation switch’s interface prevents it from disabling the port when it receives BPDUs from the new access switch.

Why Option D is Correct:BPDU guard is an STP feature that disables a port if it receives BPDUs, assuming an unauthorized device is connected. When a new access switch isconnected, it sends BPDUs as part of normal STP operation, triggering BPDU guard on the aggregation switch and disabling the port. Disabling BPDU guard on the aggregation switch’s interface (e.g., no spanning-tree bpdu-guard) allows the access switch to participate in STP without being disabled, resolving the issue while maintaining network stability.

Relevance to Certification Objectives:

Network Resiliency and Virtualization (8%):Involves troubleshooting STP mechanisms for fault tolerance.

Troubleshooting (10%):Includes diagnosing and remediating STP-related issues in campus networks.

Switching (19%):Covers Layer 2 technologies like STP and its protection features.