How to coonect to serial port

[daniel520]

hello guys,
i would like to connect to my cisco via a console port and i dont konw how

[gthill]

In the long distant past I have used minicom for serial port connections. It was once a default install on fedora. Perhaps a "yum info minicom" might help you out now.

[daniel520]

i tryed it and tryed agetty and migetty
i'm getting error no /dev/ttys0 not found in minicom

and in : agetty -h -t 60 ttys0 9600 vt 102
get empty line

[PabloTwo]

Originally Posted by daniel520

i tryed it and tryed agetty and migetty
i'm getting error no /dev/ttys0 not found in minicom

and in : agetty -h -t 60 ttys0 9600 vt 102
get empty line

For starters, there is no such thing as /dev/ttys0, but you should find /dev/ttyS0. That's with a capital "S" As always, Linux is totally case sensitive.

You can use the setserial command, as root, to view/set parameters on your serial ports. See "man setserial". By default, Fedora will usually show 4 default serial ports: ttyS0....ttyS3, even though you may only actually have one or two real serial ports. If you don't have any actual serial ports but are using a USB>Serial adapter, then the working "serial" port is /dev/ttyUSB0[1,2,3...].

To query your serial port(s) with setserial:

BASH:~/-> sudo setserial /dev/ttyS0
/dev/ttyS0, UART: 16550A, Port: 0xa000, IRQ: 16

...or to get the results returned in the format you would use to set the parameters, use the -G option:

BASH:~/-> sudo setserial -G /dev/ttyS1
/dev/ttyS1 uart unknown port 0x02f8 irq 3 baud_base 115200 spd_normal skip_test auto_irq

BASH:~/-> sudo setserial -G /dev/ttyUSB0
/dev/ttyUSB0 uart 16550A port 0x0000 irq 0 baud_base 9600 spd_normal skip_test auto_irq

On my system I have both a single real serial port (ttyS0) a one USB>Serial adapter serial port. Notice that on ttyS0 and ttyUSB0 the uarts are identified (as 16550A's). That means these are real ports. For ttyS1, the uart is reported as "unknown", which means that that port is actually non-existent..... it's a "phantom" port.

I give you this information so that you can know for sure what ports you have and what their current parameters are set to. Minicom is not the easiest program to learn. I've used it in the past a lot, but have switched to using PuTTy (yum install putty), which can provide you with a VT for a serial port with much easier GUI configuration that the minicom configuration scheme.

Also, before you can get any data to flow between your VT, whether minicom, putty or anything else, and the device connected to the serial port, the ports baud rate must be set to match the working baud rate of the device connected to it. I know nothing about Cisco routers, and what command set is used on them. Hope this helps, even if only a little.

[William Haller]

Another good GUI interface (if you are running X at least) is gtkterm.

[daniel520]

well , i tryed all this and more
GUI interface line putty , all gave the same results ..... nothing
how can i debaug the serial port
and see why it acting like this ???!

[jpollard]

You usually need a crossover cable if you are connecting a PC to
another device.... unless that device is a real terminal. A null modem
cable won't work.

Sometimes a line tester is useful for this too (a breakout box) as they
usually have LEDs for each line.

[daniel520]

its not connectivity problem for sure ,because i used same cable in windows and it connect to console

i'm missing somthing , i dont know what , but all the app that i used to connect to the serial port gave same error "unable to open serail port"

it never worked for me in any linux environment , so i think its only a setting problem
i just need to know what i'm missing here ...

[jpollard]

Out of curiosity, have you tried running minicom as root?

I think I've identified a permissions problem that doesn't occur as root.

/dev/ttyS0 (serial line) is owned by root, group dialout. Yet minicom is
neither setgid to dialout, nor does it have permissions to access via
SELinux controls.

[William Haller]

Linux also might handle signal lines like CTS, RTS, DCD, DTR, DSR and the like differently than Windows. You can't guarantee the cable will work on Linux just because it works in Windows. It probably will, but it isn't guaranteed.

As root, I've used serial cables connected to switch gear, so I know the basics work at least in F13 - haven't tried in F14 but would assume there is no change. As JPollard mentioned, there could be permission issues for regular users.

[daniel520]

well thanks guys for all the replays
i really appreciate it....

i tryed brfor minicom as root and it didnt work , but i decided ti give it a try with ttyS0 with big "S"
and yes guy .................w..........o............r........ ....k.......i........n..............g............. ............
yehhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

thanks to you all guys
just to let you know guys i also tryed puty and agetty afain with big S , nothing ,,, only minicom ..................

[PabloTwo]

jpollard may have hit on something about permissions. I am able to use /dev/ttyUSB0 as non root by adding myself (regular user account) to the dialout group. But if you are doing all this as root anyway, then adding yourself to the dialout group won't do anything to resolve your "unable to open serial port" issue. If your serial cable works in Windows, it should also work fine in Linux.

[daniel520]

thanks to you all guys for the tips and for helping me fix this problem ..

[lcamp]

minicom -S

Set it to the cisco parameters for serial interface
and change the dev to /dev/ttyS00 or /dev/ttyS01
9600 8N1 I think
then run

minicom