vCenter Server uses Microsoft ADAM/AD LDS to enable Linked Mode, which uses the Windows RPC port mapper to open RPC ports for replication. When you install vCenter Server in Linked Mode, you must modify the firewall configuration on the local machine .

Incorrect configuration of firewalls can cause licenses and roles to become inconsistent between instances.


  • The Windows version must be earlier than Windows Server 2008. For Windows Server 2008, Windows automatically configures the firewall to permit access.
  • No network-based firewalls can exist between vCenter Server Linked Mode instances. For environments with network-based firewalls, see Configure Firewall Access by Opening Selected Ports.


  1. Select Start > Run.
  2. Type firewall.cpl and click OK.
  3. Make sure that the firewall is set to allow exceptions.
  4. Click the Exceptions tab.
  5. Click Add Program.
  6. Add an exception for C:\Windows\ADAM\dsamain.exe and click OK.
  7. Click OK.