iTerm2 is my primary terminal emulator for macOS. I prefer to use a separate terminal emulator for GNS3 console (telnet) connections. After a little bit of research, I decided on Alacritty . It’s lightweight and supports the command line options we need for GNS3.

There are several different ways to install Alacritty and Telnet, but I use MacPorts in this post.


  1. Open your favorite terminal emulator (besides Alacritty πŸ˜‰).

  2. Update the local ports tree with the global MacPorts ports repository.

sudo port -d selfupdate
  1. Install Alacritty and Telnet.

inetutils is a collection of common network programs including Telnet.

sudo port -v install alacritty inetutils
  1. Get the location for Alacritty and Telnet.

Client tools from the inetutils collection have a g prefix (for GNU).

type -p alacritty gtelnet


alacritty is /opt/local/bin/alacritty
gtelnet is /opt/local/bin/gtelnet
  1. Create the Alacritty configuration directory.
mkdir -p ~/.config/alacritty
  1. Create the Alacritty configuration file.
nano ~/.config/alacritty/alacritty.toml

Enter the following:

dimensions = { columns = 80, lines = 32 }
padding = { x = 6, y = 6 }
dynamic_padding = true

normal = { family = "Andale Mono", style = "Regular" }
size = 12

background = "#4c4f55"
foreground = "#00ff00"
  • βŒƒ + o (Save) the file.
  • ⏎ to confirm.
  • βŒƒ + x (exit) the nano text editor.

Refer to Alacritty - Configuration for more information.

  1. Open the GNS3 client application.

  2. Click the Settings button.

  3. Select General on the left side menu.

  4. Click the Console applications tab.

  5. Click the Edit button.

  6. Select Custom from the drop-down menu.

  7. Enter the following in the command field:

/opt/local/bin/alacritty -T %d -e /opt/local/bin/gtelnet %h %p

Note the tool locations are from step 3.

  1. Click the Save button.

  2. Enter alacritty for the Command name value.

  3. Click the OK button.

Console setting
  1. Click the OK button to close the Command window.

  2. Click the Apply button to save the configuration.

  3. Click the OK button to close the Preferences window.

  4. Happy Labbing!

Console connection to SW1