Vmnics Might Be Down After an Upgrade to ESXi 8.0

Products

• VMware vCenter Server 8.0

Issue/Introduction

After upgrading to ESXi 8.0, vmnics might remain down if the peer physical switch does not support Media Auto Detect, or if Media Auto Detect is disabled. If the vmnic link is set down and then brought up again, the link remains down after the upgrade or installation of ESXi 8.0.

Environment

VMware vSphere ESXi 8.0

Cause

This issue occurs when the peer physical switch does not support Media Auto Detect or when the feature is disabled. After upgrading to ESXi 8.0, the VMNIC link remains down if Media Auto Detect is not enabled or properly configured.

Resolution

To resolve this issue, you have two options:

Option 1: Enable Media Auto Detect in BIOS

1. Access the host's BIOS settings by pressing F2 or opening a virtual console.
2. Navigate to the System Setup Main Menu.
3. Go to Device Settings and select the specific Broadcom NIC.
4. Enter the Device Configuration Menu.
5. Enable Media Auto Detect.
6. Reboot the host for the changes to take effect.

Option 2: Use an ESXCLI Command to Set a Fixed Speed

1. Use the following ESXCLI command to set the speed and duplex for the NIC

^{esxcli network nic set -S <your speed> -D full -n <your nic>}

      2. This command sets a fixed speed to the link and does not require a reboot.

Additional Information

net-Interface-status

Reference: VMware vCenter Server 8.0 Update 3d Release Notes