Unable to bind NICs to vSwitch and iSCSI storage volumes inaccessible

Products

• VMware vCenter Server

Issue/Introduction

• vSphere ESXi hosts are unable to reach iSCSI storage volumes.
• Attempts to bind network interface cards (NICs) to the vSwitch fail with the error message "No Nics available".
• Physical network adapters (vmnics) display as "Unassigned" in the vSphere UI.

Environment

VMware vSphere ESXi 7.x, 8.x, 9.x

Cause

The physical network adapters (vmnics) required for storage traffic are configured in an "Unassigned" state on the vSwitch, breaking the Layer 2 network path required for iSCSI target discovery.

Resolution

1. Navigate to the vSwitch configuration for the affected ESXi hosts in the vSphere Client.

2. Move the respective physical network adapters (vmnics) from the "Unassigned" list to "Active" for the required vSwitches.

3. Verify network connectivity by executing a ping from the ESXi host to the iSCSI target IP addresses.

4. Select the Software iSCSI adapter on the ESXi host and navigate to the Dynamic Discovery tab.

5. Configure the Global Storage IPs to enable SendTargets discovery.

6. Perform a storage rescan to discover the targets and mount the VMFS datastores.

Additional Information

Configure Dynamic or Static Discovery for iSCSI and iSER on ESXi Host