[GLLUG] Configuring a secondhand managed switch

[John Edwards]

Hi Chris

On Thu, Jan 30, 2025 at 05:26:35PM +0000, Chris Bell via GLLUG wrote:
> Hello,
> I have a secondhand HP ProCurve 2824 J4903 network switch and some computers 
> running Debian 12 (Bookworm) with KDE desktop and DB9 serial ports. I have 
> followed the switch "return to factory default reset" procedure, so I think  
> need to connect the Switch Console DB9 to a computer DB9 via a null-modem 
> cable to do an initial configuration with terminal configured as 
> 
> Baud rate 9600
> 8Bits + 1 stop bit
> No parity
> No flow control
> 
> Xmodem is mentioned
> I could then use a standard VT-100/ANSI or web interface to continue 
> configuration.
> 
> I have two DB9 to open end adapters plus choc block so that I can easily 
> change the connections.
> I don't care whether I work as computer user with dialup permission or root.
> I have read through various man pages, but nothing I have done so far has 
> shown any sign of working, and am not sure whether I am trying the wrong 
> software. Could SystemD need to be configured first?
> Any suggestions welcome.
> I would be happy to install a different version of Debian if needed.
> Thanks for any help.
> -- 
> Chris Bell
> www.chrisbell.org.uk

What program are you using on the Linux machine to connect?

I tend to use 'minicom'. Control-A followed by 'o' opens up the menu
(to change serial device, speed, etc), Control-A 'z' opens up help,
and Control-A 'q' quits without sending a reset to the serial device
(usually safest).

The motherboard serial devices are numbered from /dev/ttyS0, and USB
serial adapters from /dev/ttyUSB0.

The devices are usually group-writable by the "dialout" group, so run
'groups | grep dialout' to make sure you a member of that group.

I think SystemD only needs to be involved if you want to set a
terminal control on a serial device for other devices to connect to
you machine.

Another useful tool is 'statserial', which shows you the status of the
various serial pins, so you can use that to see if anything is on that
serial line and it ready to receive (eg have you got the wrong device,
crossover cable, etc).


-- 
#---------------------------------------------------------#
|    John Edwards   Email: john at cornerstonelinux.co.uk    |
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