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Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Appendix A Online Diagnostic Tests
Fabric Tests
TestFabricSnakeBackward
The TestFabricSnakeBackward test consists of two test cases: the internal snake test and the external
snake test. The internal snake test generates the test packets inside the fabric ASIC, and the test data path
is limited so that it stays inside the fabric ASIC. The external snake test generates the test packet using
the supervisor engine inband port and the test data path involves the port ASIC, the rewrite engine ASIC
inside the supervisor engine, and the fabric ASIC. Whether or not the supervisor engine local channel is
synchronized to the fabric ASIC determines which test is used. If it is synchronized, the external snake
test is used; if it is not, internal snake test is used. For both tests, only the channels that are not
synchronized to any modules are involved in the test. The backward direction indicates that the snaking
direction is from the high-numbered channel to the low-numbered channel.
TestSynchedFabChannel
The TestSynchedFabChannel test periodically checks the fabric synchronization status for both the
module and the fabric. This test is available only for fabric-enabled modules. This test is not a
packet-switching test so it does not involve the data path. This test sends an SCP control message to the
module and fabric to query the synchronization status.
Table A-47
TestFabricSnakeBackward Test Attributes
Attribute
Description
Disruptive/Nondisruptive
Nondisruptive.
Recommendation
Run on-demand. This test can result in high CPU utilization.
Default
This test runs by default during bootup or after a reset or OIR.
Release
12.1(13)E, 12.2(14)SX.
Corrective action
Supervisor engines crash to ROMMON; SFMs reset.
Hardware support
Supervisor Engine 720 and SFM.
Table A-48
TestSynchedFabChannel Test Attributes
Attribute
Description
Disruptive/Nondisruptive
Nondisruptive.
Recommendation
Do not turn this test off. Use as a health-monitoring test.
Default
On.
Release
12.1(13)E, 12.2(14)SX.
Corrective action
The module resets after five consecutive failures. Three
consecutive reset cycles results in the module powering
down. A fabric switchover may be triggered, depending on
the type of failure.
Hardware support
All fabric-enabled modules.