Firewall Configuration
UFW (Ubuntu)
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow ssh
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw enable
sudo ufw status verbose
Common Rules
sudo ufw allow from 192.168.1.0/24
sudo ufw deny from 10.0.0.1
sudo ufw limit ssh # Rate limit SSH attempts