Procedures for physical NIC replacement on ESXi hosts.

Products

• VMware vSphere ESXi

Issue/Introduction

When physical Network Interface Cards (NICs) are replaced in an ESXi host—due to hardware failure or proactive advisories—the new cards are recognized as new vmnic devices. This article provides two methods to transition networking from old NICs to new NICs on a Distributed Virtual Switch while maintaining host connectivity.

Environment

VMware ESXi 

VMware vCenter

Cause

Physical NIC replacement changes the hardware identity of the network ports. The VDS must be manually updated to map the new physical vmnic identifiers to the existing virtual uplinks.

Resolution

Method 1: Parallel Migration (Recommended if extra physical ports/slots are available)

This method is preferred as it allows both old and new NICs to be active simultaneously for a smoother transition.

1. Add two additional uplinks to the Distributed Switch (Right-click VDS > Edit Settings > Uplinks > Add uplinks).

2. Edit settings for all relevant Port Groups. Under Teaming and Failover, move the new uplinks to the Active state.

3. Configure the new physical switch ports to match the existing VLAN and Port Channel settings.

4. Place the target ESXi host into Maintenance Mode.

5. In vCenter, go to the host's Configure tab > Networking > Virtual Switches. Assign the new physical vmnics to the new uplinks.

6. Once connectivity is verified on the new NICs, remove the old vmnics from the VDS.

7. Move the new vmnics from the temporary uplinks back to the original uplink positions (e.g., move from Uplink 3 to Uplink 1).

Method 2: Sequential Migration (Standard if physical slots are limited)

Use this method if you must unplug the old NIC to insert the new one in the same slot.

1. Place the host into Maintenance Mode.

2. Create a temporary vSphere Standard Switch on the host.

3. Migrate the Management VMkernel port and one existing vmnic to the VSS to ensure you don't lose access to the host.

4. Physically replace the first NIC.

5. Ensure the new physical switch port configuration matches the old one.

6. Add the new vmnic back to the DVS. Once the first new NIC is stable on the DVS, migrate the Management VMkernel back from the VSS to the DVS.

7. Repeat the physical swap for the second NIC and add it to the DVS.

Additional Information

 

• Always perform these actions while the host is in Maintenance Mode to prevent virtual machine outages.

• Ensure the physical switch team/port-channel configuration is updated if the new NICs connect to different physical ports.