How to Set Up Minicom for Serial Access

If you want to connect to a networking device from Cisco or MikroTik, you get out-of-band access to the device over a serial console port. minicom is one of several programs that can be used to talk to these devices over a serial connection.

[A serial console port] enables administration of a machine even if it has no keyboard, mouse, monitor, or network attached to it.

Read Arch Linux wiki on working with the serial console.

Edit Configuration

To set up minicom enter:

$ minicom -s

minicom can only write its configuration file under /etc/minirc.dfl if you are root, though.

Under “Serial port setup”, set “Serial Device” to the /dev device file which is connected to the router.

When I plug in my RJ-45-rollover-USB-converter cable, it shows up under /dev/ttyUSBn (where n is a number). When I connect with my USB mini-B cable, it shows up under /dev/ttyACMn. According to the Arch wiki, a traditional hardware serial port, which, by default, modern computers do not ship with anymore, would show up under /dev/ttySn.

Set Bps/Par/Bits to 9600 8N1.

Increase Text Output Rate

To make text appear on the screen faster, increase the baud rate in IOS:

ISR4321# conf t
ISR4321(config)# line console 0
ISR4321(config-line)# speed 115200

Then, press Ctrl+P in minicom and press E to set the speed to 115200.