How to connect to a serial port on Linux

Last updated on July 2, 2020 by Dan Nanni

First of all, let's assume that you have already connected the serial port of your Linux box to a switch console port via a serial cable.

To connect a Linux terminal to the serial port of your Linux system, you can use a command-line screen manager tool called screen.

Install screen on Linux

For Ubuntu, Debian or Linux Mint:

To install screen on Ubuntu, Debian or Linux Mint:

$ sudo apt-get install screen

For CentOS, Fedora or RHEL:

To install screen on CentOS, Fedora, or RHEL:

$ sudo yum install screen

Connect to a Serial Port with screen utility

Traditionally in Linux, the first serial port (COM1) is assigned a name /dev/ttyS0, the second serial port (COM2) assigned /dev/ttyS1, etc. If you specify a serial port name as the first argument of the screen command, the current terminal window where you run screen will be directly connected to the serial port.

Thus, to connect to a serial port, simply run the following command from a terminal:

$ screen /dev/ttyS0

Optionally, you can specify baud rate (e.g., 1200, 9600, 19200) as the second parameter as follows.

$ screen /dev/ttyS0 9600

Once connected to a serial port, you will then be able to access the switch console port from the terminal.

To terminate the current screen session, type Ctrl-A+k. If you want to temporarily detach from the screen session, type Ctrl-A+d. After detached, you can re-attached to the session later by running:

$ screen -r

Support Xmodulo

This website is made possible by minimal ads and your gracious donation via PayPal or credit card

Please note that this article is published by Xmodulo.com under a Creative Commons Attribution-ShareAlike 3.0 Unported License. If you would like to use the whole or any part of this article, you need to cite this web page at Xmodulo.com as the original source.