Switch – Cisco CatOS – show port usage output

cisco-catalystswitch

I'm in the process of replacing some switch blades and i'm looking through the show port usage command on the older catos switches.

I'm struggling to understand the output for the show port usage command

(enable) show port usage 6/47

Port  Status          Last-Transition-Time
...
6/47  connected       Mon Sep 16 2013, 16:11:25    <------

That is my machine but I've restarted my machine since Sept 16th numerous times. Does restarting my machine not affect the transitioning which assume refers to rstp? (We're looking at this to see what ports we can safely unplug.

We do have a port tracking tool, but I'm cross checking this on the switch to make sure.

These ports have portfast enabled which is what I'm thinking is the cause of this, but there is no information available that describes this command.

Any help would be greatly appreciated.

Best Answer

As you found, the port is plugged into a phone; so until the phone cycles the port will stay up.

Regarding the portfast command; when a switchport comes up, spanning-tree moves through a series of states to bring the port up. Legacy spanning-tree took 15 seconds in the Listening state and another 15 seconds learning. During that time, the port cannot actually transmit traffic. portfast is a shortcut to make the port transition to a forwarding state very quickly, which is what you want as long as no switches are connected to the port.

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