Something

*nat
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A POSTROUTING -o eth0 -j MASQUERADE
COMMIT
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]

-A INPUT -i eth1 -j ACCEPT
-A FORWARD -i eth1 -o eth0 -j ACCEPT

-A INPUT -i lo -j ACCEPT

# allow established connections
-A INPUT -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT

# Mule
-A INPUT -i eth0 -p tcp --dport 9998 -j ACCEPT
-A INPUT -i eth0 -p udp --dport 9999 -j ACCEPT
-A INPUT -i eth0 -p udp --dport 10001 -j ACCEPT

# DC
-A INPUT -i eth0 -p tcp --dport 13324 -j ACCEPT
-A INPUT -i eth0 -p udp --dport 13126 -j ACCEPT

# ftp
-A INPUT -i eth0 -p tcp --dport 21 -j ACCEPT

# ssh
-A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT

COMMIT