Oracle Big Data Appliance has three in-built InfiniBand switches. Use the two NM2-GW leaf switches to connect the Oracle Exalytics machine. The Oracle Exalytics machine has one InfiniBand HCA card, but it does not include any InfiniBand switch or any instance of InfiniBand Subnet Manager.
To connect Oracle Exalytics to Oracle Big Data Appliance, you need a pair of InfiniBand cables depending on the length requirements at the datacenter. If the total distance between Exalytics and Oracle Big Data Appliance leaf switch ports is less than 10 meters, you can use copper cables. If the length is more than 10 meters, you must use fiber optic cable for InfiniBand with appropriate transceivers.