One switch attaches to an internal HCA (IOC Port8). An external leaf switch connects to 12x IB ports 1 – 4. Embedded ports 5 and 6 can be set up as a 4x IB port connecting to an external leaf switch or to a 40Gb Ethernet port. Each 40GbE port can be configured as one 40GbE port or 4x 10GbE ports.
A gateway port is a general term that includes both IB ports and Ethernet gateway ports. If your deployment requires additional ports, you can configure up to two more ports. These ports can be IB ports or 40-GbE Ethernet ports. See Configure an Additional Port.
The fabric contains an embedded SM group that manages the switching tables within the IB fabric. When there are multiple SM groups on a subnet, one SM group becomes the master SM group through an election algorithm. There is only one master SM group per subnet.
The master SM group is a key element in initializing and configuring an IB subnet. The master SM group is elected as part of the initialization process for the subnet. For more information, see Configuring IB Switching. Communication between the master SM group and the SM agents is performed through subnet management packets.