With the introduction of Windows 2008, several improvements were introduced to improve upon Microsoft's cluster technology. In order to support a multisite cluster configuration, changes in how a cluster performs its inter cluster communication or health-checks was updated. Configuring these settings is done from the command line and is detailed below:

The following links below detail this process in more detail for your consumption.

To configure heartbeat and DNS settings in a multi-site failover cluster

1. On a node in the cluster, open a Command Prompt window.
   
2. Determine whether to change the heartbeat settings, for nodes on a common subnet, nodes communicating across subnets, or both. For background information about heartbeat settings, see Requirements and Recommendations for a Multi-Site Failover Cluster (http://go.microsoft.com/fwlink/?LinkId=129109).
   By default, regardless of subnet configuration, heartbeat frequency (also known as subnet delay) is once every second (1000 milliseconds). The range for heartbeat frequency is once every 250-2000 milliseconds on a common subnet, and 250-4000 milliseconds across subnets. By default, when a node misses a series of 5 heartbeats, another node will initiate failover, and the range for this value (also known as subnet threshold) is from 3 through 10.
   
3. If in step 2 you decided to change the heartbeat settings, run one or more of the following commands. Note that the first two commands affect nodes on a common subnet and the second two commands affect communication across subnets:

   cluster /cluster:<ClusterName> /prop SameSubnetDelay=<value>

   cluster /cluster:<ClusterName> /prop SameSubnetThreshold=<value>

   cluster /cluster:<ClusterName> /prop CrossSubnetDelay=<value>

   cluster /cluster:<ClusterName> /prop CrossSubnetThreshold=<value>

4. To confirm that the heartbeat settings are set as intended, run the following command:

   cluster /cluster:<ClusterName> /prop

5. View the network names of resources that are currently configured on the cluster by running the following command:

   cluster /cluster:<ClusterName> res

6. Determine which IP addresses should be registered in DNS for your cluster: either all IP addresses on which a network name resource depends, or only the IP address that successfully comes online (that is, the IP address on the subnet of the node that currently owns that network name resource). For background information about this setting, see Requirements and Recommendations for a Multi-Site Failover Cluster http://go.microsoft.com/fwlink/?LinkId=129109.
   The default is to register only the IP address that successfully comes online.
   
7. Choose and run only one of the following commands, substituting the name of the resource for <NetworkNameResource>:
   
   • To cause all IP addresses on which a network name resource depends to be registered, run the following command:

     cluster /cluster:<ClusterName> res <NetworkNameResource> /priv RegisterAllProvidersIP=1

   • To cause only the IP address that successfully comes online to be registered, run the following command:

     cluster /cluster:<ClusterName> res <NetworkNameResource> /priv RegisterAllProvidersIP=0

8. Determine the value to use for the DNS setting called Time to Live (TTL). As an example, the value recommended for Office Exchange Server 2007 is five minutes, which equals 300 seconds. If you do not adjust the TTL value, it defaults to 20 minutes (1200 seconds). For background information about TTL, see Requirements and Recommendations for a Multi-Site Failover Cluster http://go.microsoft.com/fwlink/?LinkId=129109.
   
9. To change the TTL setting, run the following command:

   cluster /cluster:<ClusterName> res <NetworkNameResource> /priv HostRecordTTL=<TimeInSeconds>

where <NetworkNameResource> is the name of the clustered resource that you want to set the TTL value for, and <TimeInSeconds> is the value you want to set for TTL.

1. To confirm that all the DNS settings are set as intended for a given network name resource, run the following command:

cluster /cluster:<ClusterName> res <NetworkNameResource> /priv

1. Take the clustered service or application offline and bring it back online, using the method that you are most familiar with. For example, to use the Failover Cluster Management snap-in, under Services and Applications, right-click the service or application and click Take this service or application offline, then right-click again and click Bring this service or application online.

The full article as well as additional resources are listed below for your reference:

Configuring thresholds for Heartbeat Network:

• http://technet.microsoft.com/en-us/library/dd197562%28WS.10%29.aspx

Information on Windows 2008 and changes to the heartbeat algorithm:

• http://blogs.technet.com/b/askcore/archive/2010/02/12/windows-server-2008-failover-clusters-networking-part-1.aspx
• http://blogs.technet.com/b/askcore/archive/2010/02/22/windows-server-2008-failover-clusters-networking-part-2.aspx
• http://blogs.technet.com/b/askcore/archive/2010/02/25/windows-server-2008-failover-clusters-networking-part-3.aspx