Sun Microsystems IB Switch 9P Administration Manual page 116

Instead the IP address assigned to the Ethernet port of the switch is used as a basis
for unique IB subnet IDs. This approach has the nice properties that unique values
are assigned to include the switches in the site-specific management network.
Additionally, if a switch is replaced, the new switch will typically be assigned the
same IP address as the former switch, since it is taking over the "personality" of the
former switch. However, if for some reason the IP address is changed on a switch in
an operational system or a switch is replaced without updating the IP address on the
new switch, then the Solaris hosts attached to this switch will no longer be able to
communicate until a re-configuration has been performed.
Note – These aspects were not explained in the documentation for the first release of
the Sun IB switch 9p product.
The second release of the switch firmware includes three important changes:
The firmware defines a default IP address for the Ethernet port, which implies
■
that the switch can become operational without any configuration steps after
power-on.
The firmware supports more than a single predefined configuration, but the
■
configuration used in the initial firmware version is still the default.
The firmware supports cascaded switch configurations.
■
A predefined configuration is referred to as a blueprint. Hence, new commands have
been introduced in order to define which blueprint is to be used as well as which
role this switch is to have in configurations that involve more than a single switch
instance in each InfiniBand subnet.
The same black-box model for single switch configurations are supported as in the
initial release. The default configuration is the one outlined previously.
Note – If the default IB configuration (blueprint) is used, and the default IP address
for the Ethernet port is not updated, then two switches will present the same IB
subnet ID. To avoid this problem, the default IP address can not be used on both
switches, independently of whether the Ethernet port is in use on any of the
switches.
86 Sun IB Switch 9P Administration Guide • October 2006