ufw

Uncomplicated firewall

• Install

Bash

sudo apt install -y uwf

- Enable

Bash

sudo ufw enable

• Add a rule denying all incoming traffic - works on outgoing as well

Bash

sudo ufw default deny incoming 

• Check status

Bash

sudo ufw status 

Bash

sudo ufw status numbered

Bash

sudo ufw status verbose

• Reload added rules

Bash

sudo ufw reload

• Delete rule (sudo ufw status numbered)

Bash

sudo ufw delete 5

• Allow example tcp port

Bash

sudo ufw allow 223/tcp

• Allow range of ports

Bash

sudo ufw allow 30000:35000/tcp

• Allow incoming traffic from IP

Bash

sudo ufw allow from 109.xx.xx.xx

• Deny ports

Bash

sudo ufw deny 3306

Check:

digital-oceans examples