Connecting to a cisco device using serial console cable from pfsense

Snailkhan

hi
I have installed pfsense on commoditiy grade pc for my home lab and it has a serial port. nowadays all new laptps and pads etc dont have this port.

is there any possibility to establish a console connection with the switch if i connect the cable between the switch and the pfsesense serial port ?

i couldnt find an obvious package to achieve above.

dmesg | grep "uart"
uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
uart0: console (115200,n,8,1)

JKnott

You'd need to install some terminal app on pfSense. I use Minicom on Linux. However, an alternative may be to buy a USB serial port adapter. I bought one years ago and it works fine with Linux & Windows. Then again, you can also use ssh to access pfSense from another computer. It does everything you can do with a serial port.

johnpoz

I would think you should just be able to use the cu command, I just checked and pfsense has it available calling out the specific port and rate you want to use, etc.

Snailkhan

@johnpoz:

I would think you should just be able to use the cu command, I just checked and pfsense has it available calling out the specific port and rate you want to use, etc.

Thanks for the super quick response.
i red at this site
https://superuser.com/questions/476580/how-to-connect-to-cisco-w3550-with-freebsd

that command "cu -l /dev/cuau0 -s 9600" can be used to connect to cisco from freebsd . if i run it form my pfsense i get below error.
cu -l /dev/cuau0 -s 9600
/dev/cuau0: Device busy
link down

I am doing this conoluted thing as my switch blown and the only serial to usb converter at hand is not working and no pc with serial atm with me. i am locked out. above if work is a good band aid.

the speed is set correctly.

Derelict

The only Cisco device I have with USB console is a 2901 Router.

It enumerates as /dev/cuaU0 and I can cu to that but it doesn't respond at -s 9600.

I can cu to the same router just fine from a mac on /dev/cu.usbmodem141

Not sure what's up with that.

The same workflow works just fine from pfSense/FreeBSD to another ADI unit: cu -l /dev/cuaU0 -s 115200.

JKnott

and the only serial to usb converter at hand is not working

Some Cisco gear has a built in USB converter. You connect to it with a mini USB cable. I've never tried it, as I always had a USB serial port adapter. If it has one, it should work like any other USB serial port.

Grimson

Did you turn on the serial console in pfSense? In that case the port is already in use.

Derelict

That is cuau0 not cuaU0 which is why he was seeing that on cuau0.

ls -l /dev/cu*

connect the USB console.

ls -l /dev/cu*

The connected console will be the new devices.