Everything was ready out the box…

I did have fun as my configuration in my client application was set to point to an IP rather than the hostname.

Some related notes:

• SFTP: https://linuxconfig.org/how-to-setup-sftp-server-on-ubuntu-20-04-focal-fossa-linux
• https://www.howtogeek.com/50787/add-a-user-to-a-group-or-second-group-on-linux/
• https://www.digitalocean.com/community/tutorials/how-to-use-sftp-to-securely-transfer-files-with-a-remote-server
• https://wordpress.org/support/topic/the-session-allows-sftp-connections-only/

Note, I'd added the user account to the group “sftp” which then made it specifically an sftp account and blocked it for ssh using the basic configuration. I got the error “the session allows sftp connections only” when trying to ssh. Removing the account from the group fixed things.

# Create sftp group and add user
groupadd sftp
usermod -a -G sftp david
 
# Restart SSH - 2 methods
systemctl restart ssh
service ssh reload
 
# Remove user from group
gpasswd -d david sftp
 
# View groups
groups david

Disable Passwords

sudo vi /etc/ssh/sshd_config

# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication no
#PermitEmptyPasswords no

sudo systemctl restart ssh