Issues connecting with USB-console cable to Cisco switch

LaUs3r

Hey guys,

in addition to my LAN access to my Cisco 3850 I want to have a backup connection via USB-console cable (USB Type A and mini-B).

I'm desperately trying to connect from my pfSense via the USB-console cable to the switch.

Here's my status and what I tried. I hope you can help:

Status:

USB-console cable is recognized:

ugen0.2: <Cisco Cisco USB Console> at usbus0
umodem0 on uhub0
umodem0: <Cisco Cisco USB Console, class 2/0, rev 2.00/0.00, addr 10> on usbus0
umodem0: data interface 1, has no CM over data, has no break

it's added as /dev/cuaU0
Cisco handbook states the following connection details for the USB-console port:
9600 baud
8 data bits
1 stop bit
No parity
None (flow control)

Problem:
When I connect with the "cu" command, I get stuck at status "connected" and no input is recognized anymore in the shell. I need to unplug the cable in order to get input back.

[2.5.0-RELEASE][admin@pfSense]/: cu -l /dev/cuaU0 -s 9600
Connected

I tried different speeds and devices like, /dev/ttyU0. Dmesg does not indicate anything once I'm "connected" to the switch.
When I use Putty from a Windows machine, it just works perfectly.

Any hints on that?

stephenw10

That cu command should be all that is required if it's working as expected. I use that all the time to connect to other devices from pfSense. Usually other pfSense devices.

You could try using tip or screen there instead:
https://docs.netgate.com/pfsense/en/latest/hardware/connect-to-console.html#id4

Steve

LaUs3r

@stephenw10 thx for the hint. I tried tip and screen instead and got the same result. It says "connected", but instead of providing me the username prompt, it's just stuck and no keyboard input is recognized anymore.

Strangely I can connect from my NAS where I run a virtualized ubuntu using minicom.

I start to think that this is related to the USB Ports of my pfSense. Maybe I try to put minicom on the pfSense and see if someone in the Cisco forums known that behavior.

Cheers

stephenw10

Looks like it could be an issue with that device specifically. A different USB/Serial adapter may well work fine:
http://freebsd.1045724.x6.nabble.com/umodem0-Cisco-USB-serial-console-and-quirks-td6210309.html

Not seeing any updates since that suggesting it might now be supported.

Steve

LaUs3r

@stephenw10 yeah, it seems really related to the cable. If I use a USB-serial adapter with a serial-console cable it works as expected :-)