Configuring vCenter Alarms for Mismatched Uplink Speeds

Products

• VMware vCenter Server

Issue/Introduction

In a vSphere environment, network redundancy relies on consistent configurations across all physical adapters (vmnics). If one physical uplink in a team negotiates a lower speed than its peers (e.g., dropping from 10Gbps to 1Gbps), it creates an unbalanced load-balancing state. This KB provides steps to proactively alert administrators when uplink speeds within a host are inconsistent.

• Reduced network throughput for Virtual Machines.

• Intermittent latency or "jitter" in application performance.

• vMotion operations taking significantly longer than usual.

 

 

Environment

VMware vCenter Server 8.x

Resolution

Follow these steps to define a custom alarm that monitors for speed inconsistencies.

1. Target Selection

1. Log in to the vCenter UI.

2. Select the Cluster (or Datacenter) where you want to apply this rule.

3. Click the Configure tab.

4. Select Alarm Definitions from the left-hand menu.

5. Click Add to start the New Alarm Definition wizard.

2. General Details

1. Alarm Name: Host Uplink Speed Mismatch

2. Target Type: Select Hosts.

3. Click Next.

3. Setting the Trigger Condition

1. Under the IF section (Select a trigger), search for and select: "Uplink speed is different".

2. Set the Condition to trigger when this state is detected.

3. Choose the Severity (e.g., Critical) to ensure it stands out in the vSphere dashboard.

4. Defining Actions

1. Click Next to go to the Review or Actions page.

2. Toggle Send email notifications to On and enter the administrator's email.

3. Click Create to activate the alarm.