Cluster Group Failed after Network Lost

hi all,

I have a two node cluster with Windows Server 2008 Enterprise and SQL Server 2008.
the problem is when active node lost the LAN connection, the "cluster group" in Cluster Core Resources not automatically transfer to other node.

Event ID-1205    Resource Control Manager    The Cluster service failed to bring clustered service or application 'DTC01-A' completely online or offline. One or more resources may be in a failed state. This may impact the availability of the clustered service or application.

Event ID-1069    Resource Control Manager    Cluster resource 'IP Address 10.20.51.122' in clustered service or application 'DTC01-A' failed.

any help and possible solution.

Thanks,
k.rijal