So I got this idea online to make my own terminal server with a Raspberry Pi and ser2net.
- UGREEN USB to Serial RS232 Cable Adapter 4 Ports DB9 Converter 9-Pin Male to Male with Hexnuts
- Raspberry Pi
- Raspbian Stretch Lite I’m running this on Buster now
I think a Pi Zero could also do the job and save a few dollars. So far it remembers the port numbers on reboot and my config is good but I’m working on getting the logging to work the way I want it.
Install ser2net running Raspbian Stretch:
apt-get install ser2net Then edit /etc/ser2net.conf with your USB to information that I got from running “dmesg | grep tty”.
[ 4.518967] usb 1-1.5.1: pl2303 converter now attached to ttyUSB0
[ 4.523283] usb 1-1.5.2: pl2303 converter now attached to ttyUSB1
[ 4.535015] usb 1-1.5.3: pl2303 converter now attached to ttyUSB2
[ 4.539260] usb 1-1.5.4: pl2303 converter now attached to ttyUSB3
And my ser2net.conf looks like this.
2000:telnet:600:/dev/ttyUSB0:9600 8DATABITS NONE 1STOPBIT banner
2001:telnet:600:/dev/ttyUSB1:9600 8DATABITS NONE 1STOPBIT banner
2002:telnet:600:/dev/ttyUSB2:9600 8DATABITS NONE 1STOPBIT banner
2003:telnet:600:/dev/ttyUSB3:9600 8DATABITS NONE 1STOPBIT banner
apt-get install ufw
sudo ufw default deny
sudo ufw allow ssh
sudo ufw enable
sudo ufw status numbered
sudo apt-get install screen
screen -S term <to open a screen with the name term>
screen –ls to list
screen –r to reconnect
screen –r <session number> if more than one session open
ctrl +a followed by d to leave a screen open and disconnect
ctrl+d to disconnect and close the screen
jon@raspberrypi:~ $ screen -ls
There are screens on:
906.pts-0.raspberrypi (26/01/21 20:35:30) (Detached)
873.pts-0.raspberrypi (26/01/21 20:33:10) (Detached)
2 Sockets in /run/screen/S-jon.
To use the terminal server I ssh in and then run screen and open a terminal in there. The advantage to that is I can leave the terminal running during an upgrade and go get some milk and cookies.
telnet 127.0.0.1 2001
Escape character is ctrl ] and then q at the prompt to get out.