One vCenter Server instance not available in Linked Mode

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• One vCenter Server instance not available in Linked Mode
• vSphere Client connected to one of two vCenter Servers shows both the vCenter Server instances, but when a vSphere Client connection is made to the other vCenter Server, only the connected instance is available
• You see this reported for the vCenter Server instance encountering the issue:
  
  There are issues communicating with the following vCenter Server(s) : Failure to authenticate with the server

Environment

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

Cause

This issue may occur as a result of an incorrect name resolution, or if an nslookup results in an error for one of the vCenter Server's Fully Qualified Domain Name (FQDN).

Resolution

To resolve this issue:

1. Verify if there are any DNS issues using nslookup. Correct any invalid DNS entries for the vCenter Server that reports the nslookup error.
2. When the DNS entry is corrected, check if the vSphere Client connection to both the vCenter Servers shows both the instances in the vCenter inventory.
3. If the issue still exists, dis-join (Isolate) the vCenter instance from the Linked Mode, then join it back.
   
   Note: For more information on Linked Mode DNS and how to isolate and re-join a vCenter Server to a Linked Mode Group, see the vSphere Datacenter Administration Guide.

Additional Information

Note: The vCenter Server linked mode instances are shown in alphabetical order in the vCenter Server inventory.

Read-only users cannot view the inventory of all linked vCenter Servers in one vSphere Client session