HP XC System Software Hardware Preparation Guide Version 3.2

Because the first logical Gigabit Ethernet port on each node is always used for connectivity to
the administration network, there must be a second Gigabit Ethernet port on each node if you
are using Gigabit Ethernet as the interconnect.
Depending upon the hardware model, the port can be built-in or can be an installed card. Any
node with an external interface must also have a third Ethernet connection of any kind to
communicate with external networks.
3.4.3 Administration Network Interconnect Connections
In cases where an additional Gigabit Ethernet port or switch may not be available, the HP XC
System Software allows the interconnect to be configured on the administration network. When
the interconnect is configured on the administration network, only a single LAN is used.
However, be aware that configuring the system in this way may negatively impact system
performance.
To configure the interconnect on the administration network, you include the --ic=AdminNet
option on the discover command line, which is documented in the HP XC System Software
Installation Guide.
If you do not specify the --ic=AdminNet option, 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.
46 Making Node and Switch Connections