You can easily set local firewall without any advanced knowledge of networking simply by using Uncomplicated Firewall (UFW). This package is preinstalled on Ubuntu.
Basic steps to set up...
Set default rules:
Example rules for basic services:
Set logging:
Disable IPv6 if not used:
Insert line:
Enable firewall:
Check status of firewall:
Basic steps to set up...
Set default rules:
sudo ufw default deny incoming
sudo ufw default allow outgoing
Example rules for basic services:
sudo ufw limit OpenSSH
sudo ufw allow http
sudo ufw allow https
sudo ufw allow mysql
Set logging:
sudo ufw logging on
Disable IPv6 if not used:
sudo nano /etc/default/ufw
Insert line:
IPV6=no
Enable firewall:
sudo ufw enable
Check status of firewall:
sudo ufw status verbose