Ubuntu Port Firewall uwf - not via iptables

 step 1: apt install ufw

step 2: ufw enable

step 3:   sudo nano /etc/default/ufw

          #enable ipv6=yes

step 4: Added default deny of incoming and allow outgoing

   sudo ufw default deny incoming

   sudo ufw default allow outgoing

#. to see the list   

sudo ufw app list

step 5: #. Allow open ssh for all your login and other operations

sudo ufw allow OpenSSH

   sudo ufw allow ssh

   sudo ufw allow 22

   sudo ufw show added

   sudo ufw enable

step 6: #. Allow default web ports and custom ports

   sudo ufw allow http

   sudo ufw allow https

   sudo ufw allow 8099

   sudo ufw allow 88

 

#. To see the port list

   sudo ufw status verbose

#. To deny the ports

   sudo ufw deny <port>

Thank You

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu-18-04