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VMware vCenter Server displays the error: Failed to connect to host (1010837)

Symptoms

  • vCenter Server cannot connect to a host when performing operations such as:
    • Storage vMotion
    • Cold migration
    • Cloning a virtual machine
    • Deploying from template
       
       
  • The vpxa logs contain errors similar to :

    info 'Libs' opID=E3E07CA2-0000CC13-94] Cannot connect to server 190.10.20.121:902: Connection timed outinfo 'Libs' opID=E3E07CA2-0000CC13-94] CnxAuthdConnect: Returning false because CnxAuthdConnectTCP failed
    info 'Libs' opID=E3E07CA2-0000CC13-94] CnxConnectAuthd: Returning false because CnxAuthdConnect failed
    info 'Libs' opID=E3E07CA2-0000CC13-94] Cnx_Connect: Returning false because CnxConnectAuthd failed
    [2012-03-08 20:44:00.670 19F3FB90 info 'Libs' opID=E3E07CA2-0000CC13-94] Cnx_Connect: Error message: Failed to connect to server 190.10.20.121:902
    warning 'Libs' opID=E3E07CA2-0000CC13-94] [NFC ERROR] NfcNewAuthdConnectionEx: Failed to connect to peer (numRetries=0). Error: Failed to connect to server 190.10.20.121:902

  • The vpxd logs contain an entry similar to:

    [2009-06-04 19:27:16.326 'App' 4444 error] [VpxdInvtHost] IP address change for 10.223.122.143 to 10.223.127.197 not handled, SSL certificate verification is not enabled.
     
  • You see errors similar to:
    • Failed To Connect to host
    • [2009-06-04 19:27:09.952 'Libs' 3902384 warning] [NFC ERROR] NfcNewAuthdConnectionEx: Failed to connect to peer (numRetries=2). Error: Cannot connect to host 10.223.122.143: Connection timed out

  • vCenter Server shows virtual machines as being disconnected then connected.

Resolution

Cause

This issue may occur if the IP address of an ESX host is changed while being managed by vCenter Server.

Verifying the cause

To verify the cause of the issue:
  1. Log in as root to the ESX host using an SSH client.
  2. In the /etc/opt/vmware/vpxa/vpxa.cfg file, locate the Host IP address. In ESXi 5.x, the vpxa.cfg configuration file is located at /etc/vmware/vpxa/ . The entry looks similar to:

    <vpxa>
    <hostIp>10.21.48.121</hostIp>
    </vpxa>

    Note: For more information on editing files, see   Editing configuration files in VMware ESXi and ESX (1017022)
    .

Troubleshooting

If the IP address is incorrect, perform the following steps in order. If the operation does not solve the issue, proceed to the next step. Do not skip a step.

  1. Disconnect and reconnect the host:
    1. Right-click the ESX host in vCenter Server and click Disconnect.
    2. Reconnect the ESX host in vCenter Server by the Management IP address, not the hostname.

  2. Restart the VirtualCenter agent on the ESX host:
    1. Stop the vpxa service with the command:

      # service vmware-vpxa stop

      To stop the vpxa service in ESXi 5.x, run this command in the Tech Support mode.

      # /etc/init.d/vpxa stop
    2. Open the /etc/opt/vmware/vpxa/vpxa.cfg file in a text editor and correct the IP address of the ESX host.
    3. Start the vpxa service with the command:

      # service vmware-vpxa start

      To start the vpxa service in ESXi 5.x, run this command in the Tech Support mode.

      #
      /etc/init.d/vpxa start

      Note: For VMware ESXi you may need to restart all of the management agents. For more information, see   Restarting the Management agents on an ESXi or ESX host (1003490)
      .
  3. Rebuild the VirtualCenter agent configuration file on the ESX host:

    Caution: This step removes all host and virtual machine historical statistics counters. If the VMware ESX host is running virtual machines that started up in an EVC enabled environment, you may not be able to add the host back without shutting down the virtual machines first.
    1. Right-click the ESX host in vCenter Server and click Disconnect.
    2. Remove the disconnected ESX host from vCenter Server.

      Note: It has been reported that in some instances it may be necessary to disable SSL certificates in the vCenter Server > Administration > vCenter Server Settings > SSL Settings for the update to vpxd.cfg to work.The SSL certificates can be re-enabled once the ESX host has been re-added back to the vCenter Server inventory.

    3. Backup the vpxa.cfg file with the command:

      Note: In ESXi 5.x, the vpxa.cfg configuration file is located at /etc/vmware/vpxa/ .

      # mv /etc/vmware/vpxa/vpxa.cfg /etc/vmware/vpxa/vpxa.oldcfg
    4. Add the disconnected ESX host to the vCenter Server inventory.
    5. Run this command to examine the contents of /etc/opt/vmware/vpxa/vpxa.cfg and confirm that the host IP address is correct:

      # cat /etc/opt/vmware/vpxa/vpxa.cfg

      In ESXi 5.x, run this command:

      # cat /etc/vmware/vpxa/vpxa.cfg

Additional Information

If the above steps do not resolve the issue, attempt to uninstall and install the agents on the VMware ESX host. For more information, see Verifying and reinstalling the correct version of the vCenter Server agents (1003714).    
 
Note: If the ESX host is behind a NAT and the vCenter Server is on a different network, the above workaround may not address these issues or may impact other features such as HA which requires ESX hosts to communicate with each other via the actual IP and not NAT. For more information, see Using NAT between the vCenter Server system and ESXi/ESX hosts (1010652). Additionally there have been reports that the firewall had NAT turned on for the internal networks, causing this issue. This was found to be unintentional.


See Also

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