Differences

This shows you the differences between two versions of the page.

--- simple-iptables-firwall [2017/09/23 12:54] – created baumi
+++ simple-iptables-firwall [2017/10/21 18:33] (current) – baumi
@@ Line 1: / Line 1: @@
 ====== Simple iptables Firewall ======
-<code language=bash>
+<code bash>
+#!/bin/bash
+# Set default policy
+iptables -P INPUT DROP
+iptables -P OUTPUT DROP
+iptables -P FORWARD DROP
+# Flush existing rules
+iptables -F -t nat
+iptables -F -t mangle
+iptables -F -t filter
+iptables -X
+# Allow localhost traffic
+iptables -A INPUT -i lo -j ACCEPT
+iptables -A OUTPUT -o lo -j ACCEPT
+# Allow related traffic
+iptables -A INPUT -m conntrack --state ESTABLISHED -j ACCEPT
+iptables -A OUTPUT -m conntrack --state ESTABLISHED -j ACCEPT
+# Allow icmp traffic
+iptables -A INPUT -p icmp -j ACCEPT
+iptables -A OUTPUT -p icmp -j ACCEPT
+# Allow outgoing traffic
+iptables -A OUTPUT -j ACCEPT
+# Log & Drop the rest
+iptables -A INPUT -j LOG --log-prefix "INPUT "
+iptables -A INPUT -j DROP
+iptables -A FORWARD -j DROP
+iptables -A FORWARD -j LOG --log-prefix "FORWARD "
+# Show ruleset
+iptables -L -vnx
 </code>
+{{tag>kb linux iptables firewall network}}