Fix:
To diagnose a faulty Cascade module or cable perform the "Cascade External Loopback Test" from the Enhanced Hardware Diagnostic Menu. The external loopback test is a comprehensive test which tests the data path lines as well as the signal lines. It checks the communication between a switch and the installed cascade cable/module by doing an external loop-back between the - Cascade In - and - Cascade Out - of a single unit. To get to the diagnostics area the user must be directly connected to the switch in question and the following steps must be taken:
1. Connect the cascade MDA with cables to form a ring.
2. Connect a console (8bit, 9600bps, no parity) to one of the boxes and power it up or reset from front panel.
3. When you see the - Testing main memory - message, type control-C to go to the diagnostic - Press menu - .
Press 'a' to run Agent code
Press 'c' to run Cascade external loopback test
Press 'd' to Download agent code
Press 'e' to display Errors
Press 'i' to Initialize config/log flash
Press 'p' to run POST tests
Press 'r' to Receive cascade test packets
Press 's' to Send cascade test packets ...
4. Type 'c' to perform the loopback test.
a. If the test passes, it indicates that packets going in and out of the cascade module are not being corrupted.
b. If the test fails, the problem could be one of three components:
1. Bent or bad pins on the cascade cable (replace cable)
2. Bent pins or hardware issue in the cascade board (Replace cascade module)
3. Bad communication between the switch Packet Bus and cascade interface (This could indicate a Switch or cascade module. If possible try to swap a different Cascade module into the unit to see which hardware is bad. )
5. To stop test, hit any character key.
NOTE: Do not run diagnostics on a switch while in a production environment. Doing so will result in a network outage.
