Can MSCS use a second Network Interface Card (NIC) as a hot backup to a primary NIC?
MSCS can only do this for the cluster interconnect. That is, it provides the ability to use an alternate network for the cluster interconnect if the primary network fails. This eliminates an interconnect NIC from being a single point of failure. There are vendors who offer fault tolerant NICs for Windows NT Server, and these can be used for the NICs that connect the servers to the client network.