Hello,

I have just purchased my first MikroTik device (RB750Gr3) and I am trying possibly do something that it may not be capable of......Hopefully I am wrong on this.

I am trying to utilize the onboard USB port to connect up a USB-to-Serial adapter in order to connect to a Cisco switch console port because I would like to have direct out-of-band access to the switch.
I would like to be able to SSH into the MikroTik RB750Gr3 and then from that SSH session, be able to connect to the Cisco switch via the usb-to-serial adapter.

I am running routeros-mmips-6.48.2 and I am using a USB to serial adapter that has a genuine Prolific PL2303 chipset, which from what I read is supported by MikroTik routeros. See below for USB device printout.
Any advice on how to accomplish this goal would be greatly appreciated. Thank you.

This is the problem.

I have two devices with device-id="0x23c3" and device-id="0x2303". The second works the first not. (ROS 7.2.3)

0x23c3 is not " USB to Serial Bridge Controllers" but is " USB HID to I2C Bridge Controller"

From Prolific web:

Please be warned that counterfeit (fake) PL-2303HX (Chip Rev A) USB to Serial Controller ICs using Prolific's trademark logo, brandname, and device drivers, were being sold in the China market. Counterfeit IC products show exactly the same outside chip markings but generally are of poor quality and causes Windows driver compatibility issues (Yellow Mark Error Code 10 in Device Manager). We issue this warning to all our customers and consumers to avoid confusion and false purchase.

0x23c3 is not " USB to Serial Bridge Controllers" but is " USB HID to I2C Bridge Controller"

From Prolific web:

Please be warned that counterfeit (fake) PL-2303HX (Chip Rev A) USB to Serial Controller ICs using Prolific's trademark logo, brandname, and device drivers, were being sold in the China market. Counterfeit IC products show exactly the same outside chip markings but generally are of poor quality and causes Windows driver compatibility issues (Yellow Mark Error Code 10 in Device Manager). We issue this warning to all our customers and consumers to avoid confusion and false purchase.

The "Yellow Mark Error Code 10 in Device Manager" was Prolific making their new drivers not work with their old chipsets.. Counterfeit and genuine, same error. They recently fixed this though.. Their drivers work normally again, previous fix was to install an old driver version (which I did for a very long time).

This is a little off-topic from the opening post, but Google sent me here because of a similar problem: getting a USB serial console working on a PL2303 in RouterOS 7.

For any lurkers trying to find an answer for a USB Serial port on a hEX 750Gr3 running RouterOS 7:

I discovered that after upgrading from 6 to 7, even with a completely empty or default configuration, the USB serial console stopped working by default. RouterOS 6 automagically maps in the USB serial port to the console after a fresh reset, but 7 somehow seems to have lost that feature, so you're forced to connect it to a network to talk to it.

It seems to be because 7 seems to bind to a serial0 interface that the 750Gr3 does not actually have available. The console can only seem to bind to one port at a time, so after disabling the default-enabled-nonexistent serial0 under /system console, I could add and enable the USB port as a console.

This little import file works in run-after-reset during a reset-configuration to have a USB serial console on a clean slate:

Device-id="0x23a3" now works on version 7.12.1!
Perhaps 0x23c3 would work too.

(and device-id="0x23a3" still does't work on 6.49.10)