I am fairly new to Cisco Switching but had some questions as to a specific anomaly that occured with in the Cisco 3750x series switch. Scenario is as follows:
1) Customer calls in a ticket for loss of network connectivity. Tech is dispatched.
2) Logged into area router that supports customers building. Noticed through "show int eth 3/41 transceiver detail" that the RX dBm is -25. Informed tech to troubleshoot the fiber.
3) OTDR and Light Source/Power Meter tests indicate that fiber strands were good as well as the fiber patch cords. Total fiber span to include fiber patch cords was only a 2 dB loss.
4) Informed tech to change out 10Gig LR GBICs on both the router and the 3750x stack switch 1.
5) Problem followed. Informed tech to change the new GBIC on the router from blade 3/41 to blade 5/2. Problem followed.
6)Informed tech to swap out the fiber module on switch 1 with a new module (C3KX-NM-10G). Problem followed.
7) Informed tech to move new 10Gig LR GBIC and new fiber module (C3KX-NM-10G) off of switch 1 to switch 2 (te1/1/1 to te2/1/1). Issue resolved.
Question: What CLI commands could I have used to determine that switch 1 had issues that would interfere with the fiber module slot. Is switch 1 back-plane bad? How do I tell?
Switches used: (2) WS-C3750X-48P SW Version: 15.2(4)E4
Thanks.