HP StorageWorks Fabric OS 5.0.0 Command Reference Guide (AA-RW1MA-TE, May 2005)

Fabric OS 5.0.0 command reference guide 629
Loopback mode
There are four loopback modes that can be used when executing the spinSilk command. The modes
are specified by entering:
Refer to the setSplbMode command for more information on how the loopback mode setting changes
the execution of this command.
GBIC/SFP mode
If the spinSilk command is executed with GBIC mode activated, only ports containing GBICs are
tested. To activate GBIC mode, execute the following command prior to executing the spinSilk
command:
The state of the GBIC mode is saved in flash memory and remains active over a reboot until it is disabled
as follows:
Prior to running this command, make sure you disable the switch, set the GBIC mode to 1, and install
loopback cables on all GBIC ports you want to test.
Because this test includes the GBIC and the fiber cable in its test path, use the results from this test in
conjunction with the results from crossPortTest and portLoopbackTest to determine those switch
components that are not functioning properly.
• 0 for cable mode.
This loopback mode is the default mode and tests only M->N connections. It requires that
the user connect a cable from one port to a different port.
• 1 for single port also loopback mode.
This loopback mode tests M->N and M->M connections.
If M->N cable connections are used, the spinSilk command operates identically in
lb_mode 0 and lb_mode 1.
If M->M loopback plugs are used with SPLB mode disabled, the spinSilk command will
circulate frames between pairs of M->M connected ports as follows:
P1 TX >>> P1 RX -> P2 TX >>> P2 RX -> P1 TX
>>> is a cable or internal loopback.
-> is a routing table entry.
The connections between pairs of M->M ports are chosen to exercise the connections
between as many ASICs as possible, subject to the availability of pairs of M->M ports.
In mode 1 with SPLB mode disabled, the spinSilk command only circulates frames within
each single port and none of the ASIC to ASIC connections are tested. This mode should be
used only for fault isolation.
• 2 for external loopback mode.
The external loopback test creates a test loop between two ports on different ASICs; it also
tests the Serializer/Deserializer (serdes) functionality.
• 5 for internal loopback mode.
The internal loopback test creates a test loop between two ports on a single ASIC.
switch:admin> setsfpmode 1
switch:admin> setsfpmode 0