Unable to add an ESXi host to vCenter due to vSwitch configuration

Products

• VMware vCenter Server

Issue/Introduction

When attempting to add an ESXi host to vCenter, the operation fails because vCenter cannot contact the host. Despite this communication failure with vCenter, the affected ESXi host successfully responds to ICMP pings from other ESXi hosts within the same cluster.

Environment

VMware vCenter

VMware ESXi

Cause

This issue occurs because the vSwitch on the ESXi host is incorrectly configured compared to the rest of the cluster. Specifically, the load balancing policy is set to "Route based on originating virtual port" instead of the required "Route based on IP hash" (Etherchannel). Additionally, the host is missing a required uplink, utilizing only vmnic0 instead of the expected vmnic0 and vmnic1 dual-uplink configuration.

Resolution

To resolve this issue, you must update the network configuration on the host to match the existing cluster nodes:

1. Log in to the ESXi host and navigate to the vSwitch settings.
   
   
2. Change the vSwitch load balancing algorithm from "Route based on originating virtual port" to Route based on IP hash.
   
   
3. Add vmnic1 as an active uplink alongside the existing vmnic0.
   
   
4. Verify that network communication is restored.
   
   
5. Proceed to add the host to vCenter.