By using the DSS V6 iSCSI Auto Failover to present one or more targets to the MS Cluster by using only 1 VIP "virtual IP Address" to connect to the DSS V6 Target. Setting up the iSCSI Failover links are below.

http://www.open-e.com/library/how-to-resources/
Open-E Replications

2011.03 Open-E DSS V6 Synchronous Volume Replication with Failover over a LAN (broadcast)

2011.03 Open-E DSS V6 Synchronous Volume Replication with Failover over a LAN (unicast)