iptables home router

sudo iptables -F
sudo iptables -t nat -F
sudo iptables -X

sudo iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
sudo iptables -A FORWARD -i tun0 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i eth0 -o tun0 -j ACCEPT

sudo iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
sudo iptables -t nat -A POSTROUTING -o tun1 -j MASQUERADE
sudo iptables -t nat -A POSTROUTING -o tun2 -j MASQUERADE

sudo iptables -t nat -A PREROUTING -i tun0 -p tcp --dport 443 -m state --state NEW -m statistic --mode random --probability .25
sudo iptables -t nat -A PREROUTING -i tun1 -p tcp --dport 443 -m state --state NEW -m statistic --mode random --probability .33
sudo iptables -t nat -A PREROUTING -i tun2 -p tcp --dport 443 -m state --state NEW -m statistic --mode random --probability .50

sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"

=====================

*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]

# p4p1 is WAN interface, #p1p1 is LAN interface
sudo iptables -A POSTROUTING -o eth1 -j MASQUERADE

# NAT pinhole: HTTP from WAN to LAN
sudo iptables -A PREROUTING -p tcp -m tcp -i eth0 --dport 80 -j DNAT --to-destination 192.168.0.15:80

COMMIT

*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]

# Service rules

# basic global accept rules - ICMP, loopback, traceroute, established all accepted
sudo iptables -A INPUT -s 127.0.0.0/8 -d 127.0.0.0/8 -i lo -j ACCEPT
sudo iptables -A INPUT -p icmp -j ACCEPT
sudo iptables -A INPUT -m state --state ESTABLISHED -j ACCEPT

# enable traceroute rejections to get sent out
sudo iptables -A INPUT -p udp -m udp --dport 33434:33523 -j REJECT --reject-with icmp-port-unreachable

# DNS - accept from LAN
sudo iptables -A INPUT -i eth0 -p tcp --dport 53 -j ACCEPT
sudo iptables -A INPUT -i eth0 -p udp --dport 53 -j ACCEPT

# SSH - accept from LAN
sudo iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT

# DHCP client requests - accept from LAN
sudo iptables -A INPUT -i eth0 -p udp --dport 67:68 -j ACCEPT

# drop all other inbound traffic
sudo iptables -A INPUT -j DROP

# Forwarding rules

# forward packets along established/related connections
sudo iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT

# forward from LAN (p1p1) to WAN (p4p1)
sudo iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT

# allow traffic from our NAT pinhole
-A FORWARD -p tcp -d 192.168.0.15 --dport 80 -j ACCEPT

# drop all other forwarded traffic
-A FORWARD -j DROP

COMMIT