Troubleshooting vCenter Connectivity Issues due to IP Address Conflict

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

vCenter Server may experience intermittent connectivity loss, resulting in the following symptoms:

• Management access(web/SSH) instability.
• Intermittent ping drops to the gateway.
• Automated backup failures due to network related errors.

Other virtual machines on the same ESXi host and Network function normally without interruption. 

Environment

VMware vCenter Server 7.x / 8.x / 9.x
VMware vSphere ESXi 7.x / 8.x / 9.x

Cause

• This issue is caused by an IP address conflict.
• Another device or virtual machine on the network is configured with the identical IP address as the vCenter Server.
• This conflict creates a duplicate entry for the MAC address in the ARP table, causing network traffic intended for the vCenter Server to be intermittently misrouted.

Resolution

To resolve the IP conflict, identify and reconfigure the conflicting device:

1. Log in via SSH to the ESXi host where the vCenter Server resides.
2. View the host's ARP table by running: esxcli network ip neighbor list
3. Locate the vCenter Server's IP address. If the MAC address does not match the vCenter VM, note the rogue MAC address and the associated device.
4. Search the vSphere inventory for a Virtual Machine using the rogue MAC address. If not found, engage the physical network team to trace the MAC address to a physical switch port.
5. Power off the conflicting device or reconfigure it with a unique, available IP address.
6. Clear the ARP cache on the ESXi host: esxcli network ip neighbor remove -i <vCenter_IP_Address>
7. Verify that pings to the vCenter Server are stable and the UI loads without disconnects.

Additional Information

• For further assistance, contact Broadcom Support.
• Download official patches and releases via the Broadcom Support Download Center.