UFW Ubuntu Firewall

To block a port in UFW we use ufw deny command

ufw deny port/protocol

Examples

ufw deny 53

block specific IP address

The syntax is:

sudo ufw deny from {ip-address-here} to any

To block or deny all packets from 192.168.1.5, enter:

sudo ufw deny from 192.168.1.5 to any

To allow ssh service

ufw allow ssh

To see rules config file

cat /etc/ufw/before.rules|less

To enable firewall and active on boot

ufw enable