VMware vCenter Server Heartbeat - Implementing vCenter Server Heartbeat on a Single Subnet Using Dual NICs

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Summary

This article describes how to configure a non-identical node deployment of vCenter Server Heartbeat with a single subnet when network management policies prevent use of a dedicated network for channel communications.


More Information

This configuration requires two NICs, one for the Principal (Public) IP and the Management address, and a separate NIC for VMware Channel communications. Additionally, it may only be used in a V2V environment where vCenter Server Heartbeat is configured not to update DNS and there is redundancy in physical network devices in the ESX Server, for example Teamed NICs.

Please note Server Monitoring works differently in this configuration which is why it is important to have teamed NICs in the ESX host to reduce the risk of failover. Network Monitoring checks test the availability of the Principal (Public) NIC via the Management IP and not the Principal (Public) IP. Failover will occur in the following scenarios; the Channel disconnects and the Principal (Public) NIC fails or the VMware Channel disconnects and the Management IP is lost. This is different from standard vCenter Server Heartbeat deployments, where loss of the VMware Channel and the Principal (Public) NIC or the Principal (Public) IP, will cause a failover.

VMware does not support this configuration on physical servers as these should use a cross over cable if a separate network cannot be used for the VMware Channel communications or where there is a single NIC in the ESX host as temporary failure or interruption of networking could result in vCenter Server becoming unavailable or both Primary and Secondary Servers becoming active leading to a disruption of service. VMware recommends that you use adjacent IP addresses for the Principal (Public) and Management IP address.

Procedure

To configure vCenter Server Heartbeat to operate in a single subnet with dual NICs:

Follow normal installation procedures listed in Chapter 4 of the vCenter Server Heartbeat Installation Guide , Installing vCenter Server Heartbeat on Non-Identical Nodes . After installation but before starting vCenter Server Heartbeat for the first time, perform the following post installation configuration steps.

Create Static Routes

To ensure that vCenter Server Heartbeat communications are made only via the dedicated VMware Channel, create static routes for the VMware Channel on each server and configure them with the highest priority. To configure the static route, follow the steps below:

On the Primary server:

  1. Navigate to Start > Control Panel > Routing and Remote Access .
  2. Right-click Static Routes under IPv4 and select New Static Route .
  3. Select the Interface used for VMware Channel communications.
  4. Configure the Destination to the VMware Channel IP address on the Secondary server.
  5. Configure the Network Mask and Gateway .
  6. Configure the Metric to make the route most favorable for all TCP/IP connections (for example, "1").
  7. Display the routing table using the route print command to confirm that the change has taken effect.

On the Secondary server:

  1. Navigate to Start > Control Panel > Routing and Remote Access .
  2. Right-click Static Routes under IPv4 and select New Static Route .
  3. Select the Interface used for VMware Channel communications.
  4. Configure the Destination to the VMware Channel IP address on the Primary server.
  5. Configure the Network Mask and Gateway .
  6. Configure the Metric to make the route most favorable for all TCP/IP connections (for example, "1").
  7. Display the routing table using the route print command to confirm that the change has taken effect.

Configure Network Route Metrics

Change the interface metrics to make Principal (Public) network adapter more favorable than the Channel’s network adapter.

Note: These should have a lower priority than the static route previously created.

On the Primary server:

  1. Navigate to Start > Control Panel > Network Connections .
  2. Right-click on the Principal (Public) connection and select Properties .
  3. Under the list box This connection uses the following items , select the Internet Protocol (TCP/IP) or Internet Protocol Version 4 (TCP/IPv4) and then click on Properties .
  4. In the IP Protocol Properties dialog, click Advanced .
  5. Select the IP Settings tab.
  6. Clear the Automatic metric check box to disable the automatic metric calculation feature.
  7. In the text box of Interface metric, enter a metric value between 1 and 9999.

    Note: For the Principal (Public) interface, this should be higher than the one set for the VMware Channel Static Route. For VMware Channel interface this should be higher than the one set for Principal (Public) interface.
  8. Click OK to close all dialogs and save the changes.
  9. Repeat the steps for the VMware Channel connection.
  10. Display the routing table using the route print command to confirm that the changes have taken effect.

On the Secondary server:

  1. Navigate to Start > Control Panel > Network Connections .
  2. Right-click on the Principal (Public) connection and select Properties .
  3. Under the list box This connection uses the following items , select the Internet Protocol (TCP/IP) or Internet Protocol Version 4 (TCP/IPv4) and then click on Properties .
  4. In the IP Protocol Properties dialog, click Advanced .
  5. Select the IP Settings tab.
  6. Clear the Automatic metric check box to disable the automatic metric calculation feature.
  7. In the text box of Interface metric, enter a metric value between 1 and 9999.

    Note: For the Principal (Public) interface, this should be higher than the one set for the VMware Channel Static Route. For VMware Channel interface this should be higher than the one set for Principal (Public) interface.
  8. Click OK to close all dialogs and save the changes.
  9. Repeat the steps for the VMware Channel connection.
  10. Display the routing table using the route print command to confirm that the changes have taken effect.

Split-brain Avoidance

To prevent having 2 active servers (Split-brain avoidance) due to a failure of the Principal (Public) network interface card, configure vCenter Server Heartbeat as follows:

  1. Launch vCenter Server Heartbeat Console and connect to the server pair.
  2. Navigate to Server: Monitoring .
  3. Click Configure Pings to open the Ping Configuration dialog.
  4. Select the Ping Routing tab.
  5. For each server enter the Management IP so that the ping is configured from the Management IP of one server to the Management IP of the other server.
  6. Click OK .
  7. Click Configure Failover .
  8. Select the Prevent failover if channel heartbeat is lost but Active server is still visible to other servers check box.
  9. Click OK .

Note: This configuration only protects against failure of the network adapter and not the Principal (Public) IP.


Applies To

vCenter Server Heartbeat v6.3 Update 1 and Later


Related Information

None

KBID-2246

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