IBM totalstorage 326 User Reference page 173

This command behaves differently according to the modes activated
as follows:
switchEnable or switchDisable mode
v Online mode
In the online mode, where the hub is enabled prior to executing
the test, the test only tests ports that are cable-loopbacked to
ports in the same hub. Ports connected outside of the hub under
test are ignored. To run, the test must find:
– at least one port (if singlePortAlso mode is active)
– two ports (if singlePortAlso mode is not active [default])
cable-loopbacked to each other.
If this criteria is not met, the test displays the following message
in the Telnet shell:
Need at least 1 port(s) connected to run this test.
or
Need at least 2 port(s) cross-connected to run this test.
v Offline mode
In the offline mode, where the hub is disabled prior to executing
the test, it tests and expects that all ports are cable loopbacked
to similar ports in the same hub. If one or more ports are found
not connected, it aborts the test.
The test determines which port is connected to which port by
transmitting frames. As such, if any pair of ports are not properly
connected for various reasons (improperly seated GBICs or
cables, bad GBICs or cables, or improper connection of SWL to
LWL, and so on), the test ends with the following message in the
Telnet shell:
One or more ports is not active, please double-check fibres on all ports.
singlePortAlso mode
The singlePortAlso mode is specified by executing the
crossPortTest command with the second argument a value of 1 as
follows:
sw:admin> crossPortTest 0, 1
In this mode, crossPortTest allows a port to be cable-loopbacked to
itself (port M is connected to port M) in addition to the cross
connection supported (port M is connected to port N). This can be
used to isolate bad ports.
GBIC mode
Note: Ensure that you reset GBIC mode before returning the hub
to normal operation.
The GBIC mode is activated by executing the following command
prior to executing the crossPortTest command:
sw:admin> setGbicMode 1
Appendix E. Setup procedures and diagnostics for the Fibre Channel Hub
161