Re: [Nolug] console connection from linux

From: Jonathan Roberts <gremln007_at_gmail.com>
Date: Wed, 8 Dec 2010 15:41:17 -0600
Message-ID: <AANLkTim8GN1D4_E6so3pzBMB4soaiBSXsr=90=v=Y2Aw@mail.gmail.com>

Petri,

FWIW, I have had this experience with other equipment - I could only connect
during startup. Usually, power cycling the box works. Of course, you can't
always power cycle gear like this, so I expect there is another way that I
don't know.

Maybe someone on the list can shed some light on that...

Good luck!
Jonathan

On Wed, Dec 8, 2010 at 1:08 PM, Petri Laihonen <pietu@weblizards.net> wrote:

> I'll try the proposed things as soon as I get to that project again.
> Hopefully on Friday.
> Basically dmesg reports about unknown device. The distro I tried with is
> the latest LinuxMint (Not the debian edition)
>
> This I found out in Winblows via TeraTerm.... One can only start the
> communication when the switch is being started up. Trying to get the
> communication up and running when switch is on, does not work.
>
> As far as the cables, I'm not 100% certain the console cable which plugs
> into the usb is even the correct cable. However I did see at some point
> garbage being printed to the screen when I used minicom. (Really awkward
> program). Cable itself is usb <--> rj45. No in-between components. So far I
> have only been able to communicate via understandable language with another
> cable which has a serial connector. The inconvenience is that I have to get
> the switch from the networking closet to another office where the only
> computer equipped with serial connector resides.
>
> Petri
>
>
>
> On Mon, Dec 6, 2010 at 10:02 PM, James Hess <mysidia@gmail.com> wrote:
>
>> On Mon, Dec 6, 2010 at 5:09 PM, Petri Laihonen <pietu@weblizards.net>
>> wrote:
>>
>> > I'm trying to connect to the networking switch via usb to console cable.
>> > (usb <--> rj45) I have serial to rj45 cable also, but my laptop does not
>> > have serial connector.
>>
>> You mean usb<-->serial<-->rj45, right?
>> > The problem is that all info I found about this is that I'm supposed to
>> > select /dev/ttyUSB0 or similar device for connecting.
>>
>> Which distro? If you using recognized hardware, udev should create
>> the /dev/usb/ttyUSBxx
>> when device is plugged in. There can be some cases where you need to
>> manually
>> load the modules and do the
>> mknod /dev/usb/ttyUSB0 c 188 0
>> but should not be necessary or desired on a modern distro.
>>
>> Watch the output of the 'dmesg' command, run dmesg before and after
>> plugging in the USB,
>> within a few seconds, dmesg should show the name of a device that has been
>> attached, if it is detected, and that it is a usb serial device, if
>> dmesg does not show anything new,
>> then device is broken or you need drivers, and you need to know what
>> model/chip
>> serial device you have, so you can find the right
>> driver, or get the drivers from the manufacturer.
>>
>> If the manufacturer can't provide a proper driver, and you need to
>> replace..
>> I am a big fan of the Prolific PL2303 chip based dongles, because
>> there are open source drivers in the Linux kernel proper and open
>> source OSX drivers as well,
>> Linux kernel should have those if built using CONFIG_USB_SERIAL_PL2303.
>>
>> which is the default for major distributions for the past 5 years at least
>> Look for usbserial.ko and pl2303.ko files, in your modules directory
>>
>> You might want to check the general state of which USB modules you
>> have with your installed kernel.
>>
>> for i in /lib/modules/$(uname -r)/kernel/drivers/usb/serial/*.ko ; do
>> modinfo $i ; done|grep description
>>
>> --
>> -JH
>> ___________________
>> Nolug mailing list
>> nolug@nolug.org
>>
>
>

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Received on 12/08/10

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