The clustered mailbox server does not fail over after a cluster node loses the public network connection in Exchange Server 2007

After a cluster node loses the public network connection in Microsoft Exchange Server 2007 Enterprise Edition, the IP address resource changes to a failed state. However, the clustered mailbox server does not fail over to another node in the cluster.

When this issue occurs, the following events are logged in the System log:

Event Type: Error
Event Source: ClusSvc
Event Category: IP Address Resource
Event ID: 1077
Date: 3/27/2007
Time: 5:41:51 AM
User: N/A
Computer: Node-CL2
Description: The TCP/IP interface for Cluster IP Address 'IP Address (name)' has failed.

Event Type: Error
Event Source: ClusSvc
Event Category: Failover Mgr
Event ID: 1069
Date: 3/27/2007
Time: 5:41:51 AM
User: N/A
Computer: Node-CL2
Description: Cluster resource 'IP Address (name)' in Resource Group 'group' failed.

This issue occurs when more than one clustered mailbox server failover occurs in a one-hour interval. By default, one failover within one hour is allowed for a clustered mailbox server in Exchange Server 2007.

Note In Microsoft Exchange Server 2003, the default setting is ten failovers within six hours.

This issue typically occurs during the testing phase of an Exchange Server 2007 cluster. For example, this issue may occur if you simulate a network issue on cluster node1 and then simulate the issue on cluster node2 within one hour.

To resolve this issue, modify the default failover threshold setting if the circumstances in your organization predispose you to experience this issue. Although we believe that the default setting is appropriate for clustered production environments, you may decide to modify the default setting during the testing phase of an Exchange Server 2007 cluster.

To modify the default failover threshold setting, follow these steps:

1. Start the Cluster Administrator Microsoft Management Console (MMC) snap-in.
2. Locate and then right-click the cluster group object for the clustered mailbox server, and then click Properties.
3. Click the Failover tab.
4. Change the Threshold value to 10.
5. Click Apply, and then click OK.

Note After you successfully finish the testing phase of an Exchange Server 2007 cluster, we recommend that you set the default failover values for the cluster group object back to one failover within one hour.