I've consulted a number of guides, switched a number of rules about, everything else works fine, I just cannot get the ports to forward.

Here be my current script:
Code:
#! /bin/sh
echo 0 > /proc/sys/net/ipv4/ip_forward

export LAN=eth0
export WAN=eth1

iptables -t nat -F POSTROUTING
iptables -t nat -F PREROUTING
iptables -t nat -F OUTPUT
iptables -F

iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT

iptables -A FORWARD -j ACCEPT -p tcp --dport 59927
iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 59927 -j DNAT --to 10.1.2.100:59927
iptables -A FORWARD -j ACCEPT -p udp --dport 59927
iptables -t nat -A PREROUTING -i eth1 -p udp --dport 59927 -j DNAT --to 10.1.2.100:59927

iptables -t nat -A POSTROUTING -s 10.1.2.0/24 -j MASQUERADE
iptables -A FORWARD -j ACCEPT -i ${LAN} -s 10.1.2.0/24
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT

iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

iptables -I INPUT 1 -i ${LAN} -j ACCEPT
iptables -I INPUT 1 -i lo -j ACCEPT
iptables -A INPUT -p UDP --dport bootps -i ! ${LAN} -j REJECT
iptables -A INPUT -p UDP --dport domain -i ! ${LAN} -j REJECT

iptables -A INPUT -p TCP -i ! ${LAN} -d 0/0 --dport 0:1023 -j DROP
iptables -A INPUT -p UDP -i ! ${LAN} -d 0/0 --dport 0:1023 -j DROP

iptables -I FORWARD -i ${LAN} -d 10.1.2.0/255.255.255.0 -j DROP
iptables -A FORWARD -i ${LAN} -s 10.1.2.0/255.255.255.0 -j ACCEPT
iptables -A FORWARD -i ${WAN} -d 10.1.2.0/255.255.255.0 -j ACCEPT
iptables -t nat -A POSTROUTING -o ${WAN} -j MASQUERADE

echo 1 > /proc/sys/net/ipv4/ip_forward
Thanks in advance.