Problem Solved -- Connecting to Console Port SG-1100 (Linux)

[d3m5]

Running Ubuntu 18.04, attempting to connect to the Console Port (USB to Serial adapter in the SG-1100) was unsuccessful. But I found the solution. Hope this helps someone ...

PuTTY
I tried installing putty, but putty would not connect to the serial port. dmesg indicated that the pl2303 was being recognized, the correct driver was installed, and the port was indeed /dev/ttyUSB0. But putty failed with:

(putty:1657) Gtk-CRITICAL ... gtk_box_gadget_distribute ... failed in GtkScrollbar

I finally gave up on PuTTY.

cu
The cu command also failed. I tried

$ cu -l /dev/ttyUSB0 -s 115200

but even if i ran it as root (sudo ...) it failed.

cu: open (/dev/ttyUSB0): permission denied
cu: /dev/ttyUSB0: Line in use

lsof showed that there were no processes using that device.

screen
I installed screen

$ sudo apt-get install screen

and then ran

$ sudo screen /dev/ttyUSB0 115200

Success! I'm in.

[chrismacmahon]

Yes, screen is amazing.

This is why we suggest it in our help document:
https://docs.netgate.com/pfsense/en/latest/solutions/sg-1100/connect-to-console.html#gnu-screen