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by anonymous
I've connected a USB>Serial cable to the Rutx09. I've attached a Cisco switch to the serial connector. I can access the Cisco switch over the network by telnetting to the configured port. But when I issue a carriage return, I get the prompt twice instead of once. When I enter "show running" it displays the config, until the screen/pager is filled and stops (like someone pressed "q" instead of "space"). I've played with the "Echo" and "No loading zeros" settings, but they don't seem to be of any influence. Any ideas how to get a "normal" working serial connection?

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by anonymous


Just to confirm whether there's an issue in general - I've tested this on my end using USB to RS232 adapter with Cisco 2921 con0 port and a RUTX router. Everything seems to be in order and while the communication/responses are slower due to low baud rate, everything seems to work well. This indicates that the issue may be isolated on some specific devices.

Could you please clarify what model Cisco switch is it and what console settings have you configured on the RUTX09? In addition, how exactly do you get into the switch - is it via SSH from the RUTX09 and then into the CLI of Cisco switch by issuing a command on RUTX09 "microcom /dev/..." or do you add some extra flags along the microcom command?

Best regards,


Best answer
by anonymous
I've tested both on a Cisco 3750 switch and Fortigate 40F firewall. Both devices work fine on my laptop or the serial console server we have. So I'm suspecting the USB cable/chipset to be the issue. Serial settings are all default. Is there a recommendation on USB cable/chipset? I see cables for $10 on Amazon (USB > RJ45), but there are also more expensive cables (>$30). I've done a telnet on <port> on the Rutx09 itself, since the serial service is listening on by default. No additional commands or settings.
by anonymous
We don't have any recommendations in particular. I've used relatively cheap (~7 EUR) USB (male) to RS232 (male) adapter during my testing. Connected devices like so:

RUTX09 <> USB (male) ----- RS232 (male) <> RS232 (female)  ----- RJ45 <> Cisco 2921

However, I'd like to note that for the console part I did use official RS232 (female) to RJ45 console adapter from Cisco. I don't have another adapter at the moment but I'll try to obtain a different USB-RS232 adapter at some point during this or next week and see if a similar issue occurs.

Meanwhile, would it be possible to try connecting to the Cisco switch using a different adapter on your end? Also, what firmware version is running on the RUTX09? I was performing my tests with the latest (7.01.4) firmware version.
by anonymous
I've just changed the cable with a $10 one from Amazon (USB>RJ45 with FTDI chipset) and that works like a charm. So it's just a no name cable issue. Thanks!

Do you happen to know the escape character? According to microcom it's CTRL-.q but that doesn't work.
by anonymous
Found the escape sequence for the serial console: CTRL SHIFT X

Might be usefull to add this to the documentation regarding the serial port.