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ESXi/ESX hosts enter a Not Responding state after connecting to vCenter Server (1002719)

Details

  • An ESXi/ESX host connects to vCenter Server, but after several seconds, it becomes disconnected or changes to a Not Responding state.
  • Trying to reconnect fails and the host changes to an unresponsive state.
  • Direct connection to the ESXi/ESX host with the vSphere Client works normally.
  • Ping and other network connectivity testing works without any issues.
  • There are no abusive session timeout configurations on the firewall.
  • hostd and vpxa processes and logs do not show any responsiveness issues.

Solution

This issue may occur in these scenarios:
  • A firewall prevents port 902 UDP heartbeats from the ESXi/ESX host from reaching the vCenter Server.

    This issue occurs when the ESXi/ESX host firewall or another firewall between the ESXi/ESX host and vCenter Server is configured to filter the UDP packets.

    Note: ESXi automatically opens its firewall when the vCenter Server agent is installed.

    To resolve this issue:

    • For an ESX firewall:

      1. Run this command to temporarily disable the ESX firewall and determine if it is blocking the port 902 UDP heartbeat packets:

        service firewall stop

      2. Try connecting the ESX host to vCenter Server. If it stays connected, there is a misconfiguration/corruption of the firewall. For more information, see 1001081.

      3. If the ESX host continues to appear Disconnected or Not Responding, run Ethereal on the vCenter Server NIC to confirm if the port 902 UDP packets arrive.

    • For a Windows or third-party firewall:

      1. Disable the firewall.
      2. Try connecting the ESX host to vCenter Server. If it stays connected, there is a misconfiguration/corruption of the firewall. Ensure that the firewall is not blocking UDP port 902.


  • Network Address Translation (NAT) between vCenter Server and the ESXi/ESX host is preventing port 902 UDP heartbeats from arriving at vCenter Server.

    Note: Network Address Translation (NAT) is not a supported network configuration. For more information, see the vCenter Server Prerequisites section in the VMware vSphere Installation Guide for your version.

    • Starting with VirtualCenter 2.0.1 patch 2, an explicit heartbeat IP address can be advertised by VirtualCenter. To do so:

      1. Add a managedip entry to the vpxd.cfg configuration file and include the IP address of vCenter Server.

        Note: By default, the vpxd.cfg file is located at:

        C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter.

        Example:

        <vpxd>
        ...
        <managedip>IP_address</managedip>
        ...
        </vpxd>


        Where IP_address is the actual IP address of the VirtualCenter server.

      2. Restart the VMware VirtualCenter Server service after adding the entry.

    • For VirtualCenter 2.5 and later, the IP address to use for heartbeats can be specified in the VMware Infrastructure Client. To do so:

      1. Log into the VirtualCenter server using the VI or vSphere Client.
      2. Click Administration > VirtualCenter Management Server Configuration.
      3. Click Runtime Setting.
      4. Set Managed IP Address to the IP address to which the ESX host should send the heartbeats.

Additional Information


For a complete list of TCP/UDP ports used, see TCP and UDP Ports required to access vCenter Server, ESXi/ESX hosts, and other network components (1012382).

For more information on possible issues, see:

For translated versions of this article, see:

This Article Replaces

2001278

Update History

07/07/2011 - Clarified information about conflicting firewalls. 011/11/2013 - Added ESXi 5.5 and vCenter Server 5.5 to Product

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