The Summary tab in vCenter Server displays all hosts within the HA cluster with the warning: Host could not reach isolation address: none specified

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• In the Summary tab of vCenter Server, all hosts within the HA cluster appear with the warning:
  
  Host <FQDN> could not reach isolation address: none specified
  
  Where <FQDN> is the FQDN of the host.

Environment

VMware vCenter Server 4.1.x
VMware ESX 4.0.x
VMware vCenter Server 4.0.x
VMware ESX 4.1.x

Resolution

This issue may occur if the default gateway has been modified on the ESX/ESXi hosts.

To resolve this issue:

1. In the vCenter Server inventory, right-click the cluster and click Edit Settings.
2. Navigate to VMware HA > Advanced Option.

3. In the next available empty Option field, enter das.isolationaddress.

4. In the Value field associated with the Option field, in Step 3, enter the default gateway IP address in the value field.

5. Right-click each host in the cluster and click Reconfigure for HA.

For more information, see VMware High Availability cluster reports the error: Could not reach isolation address (1002787).

Additional Information

VMware High Availability cluster reports the error: Could not reach isolation address