Elena,
In a "real" Clustered ONTAP environment, the Cluster Network is a private network not accessible from client or servers. For the simulator, I usually set these as "Host-Only". This allows them only to talk to each other.
The other 2 interfaces are for data traffic. I usually set these to NAT. With NAT, I can get to them from my host machine for mounting CIFS shares, and presenting iSCSI LUN's. Regardless of what network my host is connected to, my NAT network always keeps the same private LAN/IP range. I have attached a screenshot of what my config looks like...
