First remote login | howto.cogip.be

Sudo user mountdoom has previously been created on baggins; see User management to proceed.
From a terminal, connect to the Pi, which ip is 192.168.0.10

BASH

ssh mountdoom@192.168.0.10

Enforce connection security

Enable SSH key auth

See SSH key authentification

Disable remote password logins for all users

BASH

/boot/dietpi/func/dietpi-set_software disable_ssh_password_logins 1

Change dropbear SSH port

BASH

sudo nano /etc/default/dropbear

Adapt line to desired port

INI

# The TCP port that Dropbear listens on
DROPBEAR_PORT=2022

After reboot / reload, connect with

BASH

ssh -p 2022 mordor

Or change alias in

.ssh/config

Host mordor
  HostName remote.ip.address
  Port 2022
  User mountdoom
  IdentityFile ~/.ssh/mordor

And connect with

BASH

ssh mordor

Firewall

BASH

sudo apt update
sudo apt install ufw

Add an exception for the current connection

BASH

sudo ufw allow 2022/tcp comment 'SSH custom'

Activate UFW

BASH

sudo ufw enable

Optional: restrict SSH connection to one LAN ip

In this example, the local client ip we're connecting from is 192.168.0.20

BASH

sudo ufw allow from 192.168.0.20 to any port 2022 proto tcp comment 'SSH dedicated'

Check line numbers of unnecessary rules

BASH

sudo ufw status numbered

Status: active

     To                         Action      From
     --                         ------      ----
[ 1] 2022/tcp                   ALLOW IN    Anywhere                   # SSH custom
[ 2] 2022/tcp                   ALLOW IN    192.168.0.20               # SSH dedicated
[ 3] 2022/tcp (v6)              ALLOW IN    Anywhere (v6)              # SSH custom

Remove them with

BASH

sudo ufw delete 3
sudo ufw delete 1

And reload UFW

BASH

sudo ufw reload