Bash script to configure iptables for a web server. Some rules can be removed depending on used services.

iptables-config-script

#!/bin/sh

# Empty all rules
sudo iptables -t filter -F
sudo iptables -t filter -X

# Set up default rules
sudo iptables -t filter -P INPUT DROP
sudo iptables -t filter -P FORWARD DROP
sudo iptables -t filter -P OUTPUT ACCEPT

# Authorize already established connexions
sudo iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

# Authorize loopback
sudo iptables -t filter -A INPUT -i lo -j ACCEPT

# ICMP (Ping)
sudo iptables -t filter -A INPUT -p icmp -j ACCEPT

# SSH
sudo iptables -t filter -A INPUT -p tcp --dport 22 -j ACCEPT

# HTTP
sudo iptables -t filter -A INPUT -p tcp --dport 80 -j ACCEPT

# HTTPS
sudo iptables -t filter -A INPUT -p tcp --dport 443 -j ACCEPT