If you do not specify the --ic=AdminNetoption, the discover command attempts to locate the highest speed interconnect on the system with the default being a Gigabit Ethernet network that is separate from the administration network.

3.4.4 Myrinet Interconnect Connections

The supported Myrinet interconnects do not have the ordering requirements of the Quadrics interconnect, but it makes sense to structure it in parallel with the other two networks in order to make the connections easy to maintain and service.

3.4.5 InfiniBand Interconnect Connections

The supported InfiniBand interconnects do not have the ordering requirements of the Quadrics interconnect, but it makes sense to structure it in parallel with the other two networks in order to make the connections easy to maintain and service.

If you use a dual-ported InfiniBand host channel adapter (HCA), you must connect the IB cable to the lowest-numbered port on the HCAs; it is labeled either Port 1 or P1. This is necessary so that the OpenFabrics Enterprise Distribution (OFED) driver activates the IP interface called ib0 instead of ib1.

58 Making Node and Switch Connections