The Install Guide mentions Ethernet only:
Under Hardware Requirements, it says:
Ethernet controllers
In addition to the built-in public Ethernet controller, VCS requires at least one more Ethernet interface per system. Symantec recommends two additional interfaces.
.....
To set up the hardware
Connect the Storage Foundation private Ethernet controllers.
Perform the following tasks as necessary:
■ When you add nodes to a two-node cluster, use independent switches or hubs for the private network connections. You can only use crossover cables for a two-node cluster, so you might have to swap out the cable for a switch or hub.
■ If you already use independent hubs, connect the two Ethernet controllers on the new node to the independent hubs.
