iptables_example

*filter

# Dropping incoming connections that don't have explicit rules below
:INPUT DROP [68:4456]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [1628:151823]

# Allow localhost
-A INPUT -i lo -j ACCEPT

# Allow established connections for both public and private connections
-A INPUT -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT

# Opening ports wide open
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT

# Allow ICMP
-A INPUT -p icmp --icmp-type echo-request -j ACCEPT
-A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT

# Opening a port to a specific IP
# -A INPUT -p tcp -m tcp --dport 8080 -s x.x.x.x -j ACCEPT

# Opening a port to a range of IPs
# -A INPUT -p tcp -m tcp --dport 20000 -s 192.168.0.0/24 -j ACCEPT

# Commmiting the rules to the firewall
COMMIT