Ufw on debian

* install

apt  install ufw
 

* Configuration

 ufw enable 
Command may disrupt existing ssh connections. Proceed with operation (y|n)? y
Firewall is active and enabled on system startup



ufw default deny incoming
ufw default allow outgoing

ufw status verbose

* Firewall Rules

 ufw app list
 

 ufw  allow 'SSH'
 ufw  allow WWW #其实就是80

 
 
 ufw allow 'Nginx HTTP'


ufw allow 53/tcp 

** Port Ranges

Port ranges may also be specified, a simple example for tcp would be:

  ufw allow 1000:2000/tcp

and for udp:

  ufw allow 1000:2000/udp

** IP address

An IP address may also be used:

 ufw allow from 111.222.333.444

* Deleting Rules

Rules may be deleted with the following command:

 ufw delete allow ssh

* see also

https://wiki.debian.org/Uncomplicated%20Firewall%20%28ufw%29

https://help.ubuntu.com/community/UFW

https://www.digitalocean.com/community/tutorials/how-to-setup-a-firewall-with-ufw-on-an-ubuntu-and-debian-cloud-server