Jims' Network Diary – musings of a network admin

Installed my 3750 stack recently, and thought I’d record some useful diagnostics commands.

switch#show switch

Shows the members of the stack, their respective MAC addresses and their priority. A higher priority number is better.

switch#show switch stack-ports

Shows the status of the stacking ports. I used this, in combination with swapping cables to diagnose a faulty stacking port on a reconditioned 3750 I purchased.

#show switch stack-ports summary

Shows Port status, cable lengths, link statuses.

#show switch stack-ring speed

Another useful one to verify that stacking cables and ports are working correctly. If there are two cables between switches in a two switch stack, they should be running at 32G / “Full”.