Ubuntu’s firewall (UFW)

What is UFW

Links

Details from

1. digitalocean

2. random google result

Why did I use it

1. when a new vps was created, all ports were closed EXCEPT OpenSSH

2. later, when testing some docker stuff - for example during installing bookstackapp - all ports were closed and so, I had to open https as

sudo ufw allow https

OR

sudo ufw allow 443

1. To check which ports are open

sudo ufw status

1. allow firewall (ufw) to keep ssh ports open

ufw allow OpenSSH

1. main-step: enable firewall

ufw enable

1. Something goes wrong

sudo ufw reset