Issue

After installing the desktop version of Ubuntu 20.04 on my computer, I found that computers on the LAN cannot connect it via ssh.

$ ssh test@192.168.8.6
ssh: connect to host 192.168.8.6 port 22: Connection refused

Solution

The SSH server is not installed by default on Ubuntu desktop systems but it can easily install openssh-server by running apt.

sudo apt update
sudo apt install openssh-server

Run again after successful installation.

$ ssh test@192.168.8.6                                                                 
cpm@192.168.8.6's password: 
Welcome to Ubuntu 20.04.3 LTS (GNU/Linux 5.11.0-27-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

182 updates can be applied immediately.
107 of these updates are standard security updates.
To see these additional updates run: apt list --upgradable

Your Hardware Enablement Stack (HWE) is supported until April 2025.
Last login: Mon Dec 13 21:56:52 2021 from 192.168.8.123​