How to verify physical NIC speed capabilities and support on ESXi hosts

Products

• VMware vSphere ESXi

Issue/Introduction

• Administrators may need to verify if a physical network interface card (NIC) supports specific speeds (e.g., 10Mbps, 100Mbps, 1000Mbps, or 10Gbps) for manual configuration or troubleshooting network negotiation issues.
• In ESXi host, the available speed and duplex settings are dynamically populated based on the hardware's advertisement.
• If a specific speed is missing from the configuration options in the vSphere Client or the command-line output, it indicates that the underlying hardware or firmware does not support that speed specification.

Environment

VMware ESXi

Resolution

Following steps can be used to check the Physical NIC speed capabilities:

Method 1: Command Line Interface

• Enable and log in to the ESXi Shell or SSH as root.

• Identify the available physical adapters by running: esxcli network nic list

• Check the specific capabilities of the NIC (e.g., vmnic2) by running: esxcli network nic get -n vmnic2

• Locate the "Advertised Link Modes" line in the output.
  
  

Method 2: vSphere Host Client (UI)

1. Log in to the ESXi Host Client (https://<ESXi-IP>/ui).

2. Navigate to Networking > Physical NICs.

3. Select the target NIC and click Edit settings.

4. Drop down the Speed menu to view available options.

Note: If a speed is not explicitly listed in this output, the NIC hardware does not support that speed.

 

Additional Information

Configuring the speed and duplex of an ESXi host network adapter