IBM 2109 - SAN Fibre Channel Switch Model S16, Service Manual

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on each port back to the receiver on the same port by way of an internal hardware
loopback. It tests the switch circuitry up to the serial output of the ASIC.
The loopback point chosen by the portLoopbackTest depends on what kind of GBIC
module is present. If a GBIC other than an optical SWL or LWL GBIC is present,
the test loops back only at the input (rather than the output) of the serial link.
Copper and unknown GBIC types fall within this category.
The command syntax is.
portLoopbackTest nFrames
Attention: This command cannot be performed on an operational switch. Before
issuing the portLoopbackTest command, disable the switch by using the
switchDisable command.
If you do not include the nFrames parameter, the loopback test runs continuously
until you press Enter again. If the test does not find an error, there is no output. You
can choose to continue the test, view statistics, or view an error log. Table 35
explains the loopback errors message fields.
While the test is running, all interface module front panel LEDs rapidly flicker green,
indicating that the test is finding no errors and is processing.
Table 35. portLoopbackTest command field descriptions
Field Description
Diagnostics Status The title header displays the time the diagShow command was
performed.
port# The port number.
diags The current diagnostic status of the port.
Possible values include
OK
,
BAD
.
switch:admin> portLoopback Test
Running Port Loopback Test ....
Diags: (Q)uit,
(C)ontinue, (S)tats, (L)og: s
Diagnostics Status: Sun Jan 1 00:00:00 2000
port#: 0 1 2 3 4 5 6 7
diags: OK OK OK OK OK OK OK OK
state: UP UP UP UP UP UP UP UP
lm0:
lm1:
lm2
lm3
lm4
lm5
lm6
lm7
4654 frTx
4654 frTx
4654 frTx
4654 frTx
4654 frTx
4654 frTx
4654 frTx
4654 frTx 4654 frRx
4654 frRx
4654 frRx
4654 frRx
4654 frRx
4654 frRx
4654 frRx
4654 frRx 0
0
0
0
0
0
0
0 LLI_errs.
LLI_errs.
LLI_errs.
LLI_errs.
LLI_errs.
LLI_errs.
LLI_errs.
LLI_errs.
Central Memory OK
Total Diag Frames Tx: 38032
Total Diag Frames Rx: 39232
Diags: (Q)uit, (C)ontinue, (S)tats, (L)og: q
aborted
Figure 55. portLoopbackTest command example
Appendix B. Diagnostics
109