Don't charge your Airconsole (or mobile phone) on your switch's USB port!

I use an Airconsole to connect to switch console ports most of the time so that I can go sit at my portable table instead of standing on a ladder. It's a lot safer and more comfortable, especially when the switch is in a cabinet 10 or 12 feet up.

The Airconsole is charged using a USB micro port so I carry a short USB-A to USB-micro cable and plug it into the switch's USB port if it has one. I have been doing this a long time and never had an issue.

Last night I was working on a Cisco 4500-x switch and connected my Airconsole to the USB port. I was connected for a couple hours working on the initial configuration and testing without any issues. Then I did a "write mem" and removed the power cords so that they could be routed and dressed into the rack.

When the switch was powered back up it wouldn't boot and rapidly displayed this error message on the Airconsole over and over without ever continuing to boot:

Feb 16 18:50:47 %IOSXE-3-PLATFORM: process kernel: [ 77.606565] hub 1-0:1.0: over-current change on port 1
Feb 16 18:50:47 %IOSXE-3-PLATFORM: process kernel: [ 77.710565] hub 1-0:1.0: over-current change on port 1
Feb 16 18:50:47 %IOSXE-3-PLATFORM: process kernel: [ 77.814564] hub 1-0:1.0: over-current change on port 1
Feb 16 18:50:47 %IOSXE-3-PLATFORM: process kernel: [ 77.918564] hub 1-0:1.0: over-current change on port 1
Feb 16 18:50:47 %IOSXE-3-PLATFORM: process kernel: [ 78.022564] hub 1-0:1.0: over-current change on port 1
Feb 16 18:50:47 %IOSXE-3-PLATFORM: process kernel: [ 78.126564] hub 1-0:1.0: over-current change on port 1

I had added a third party DAC cable to switchport 1 right before I powered down and thought it was referring to switchport 1 so removed the DAC cable but it didn't make any difference. Then I noticed that the Airconsole charge LED was flashing at the same rate as the error messages. I removed the USB cable from the switch and it booted normally!

Recently I purchased a Micro USB 4 Active POE "Splitter Power Over Ethernet 48V to 5V 2.4A Raspberry Pi" on ebay (Amazon sells the same device for about the same cost).

I use it on switches with PoE instead of the USB cable but the 4500-x is fiber only. But, I carry some longer patch cables with me so I could have charged off a 2960-x PoE+ port and still been able to reach the 4500-x.

This splitter has a micro USB connector on it and an RJ45 male so you can put it inline if there aren't any open ports available.

I also bought one with a barrel connector to power my Odroid XU4 Kali box. Make sure you purchase the one with the micro-USB connector.