Can anyone give me a clue? The basics are:
1 machine: SuSE 8.2
3 nics
2 internal networks (examples):
$INTLAN1:> 192.0.0.2 $INTLAN2:> 192.0.5.2

3 good ip's (examples):
eth0> 128.0.0.1 eth0:1> 128.0.0.2 eth0:2> 128.0.0.3

2 spoofed ip's:
$INTIF1> 192.0.5.2 $INTIF2> 192.0.48.3

works:
-connecting from the internet/external LAN to all machines via (ssh, FTP, HTTP)

not:
-connecting between $INTLAN1 & $INTLAN2
-samba connections from anywhere
-afp (apple) connections from anywhere

-Thanks in advance....

#!/bin/sh
PATH="$PATH:/usr/bin/:/usr/sbin"
DEPMOD=/sbin/depmod
INSMOD=/sbin/insmod
EXTIF=eth0
INTIF1=eth1
INTIF2=eth2

case "$1" in
'start')
echo "Clearing any existing rules and setting default policy.."
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -F
iptables -F INPUT
iptables -F OUTPUT
iptables -F FORWARD
iptables -X
iptables -t nat -F
# loopback rules
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -i $EXTIF -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -o $EXTIF -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i $EXTIF -j ACCEPT
echo "Adding Masquerade support for 192.0.0.0 subnet..."
iptables -A FORWARD -i $EXTIF -o $INTIF1 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i $INTIF1 -o $EXTIF -j ACCEPT
echo "Adding Masquerade support for 192.0.5.0 subnet..."
iptables -A FORWARD -i $EXTIF -o $INTIF2 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i $INTIF2 -o $EXTIF -j ACCEPT
echo "Allowing traffic between internal networks..."
iptables -A FORWARD -i $INTIF1 -o $INTIF2 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i $INTIF2 -o $INTIF1 -j ACCEPT
iptables -A FORWARD -i $INTIF2 -o $INTIF1 -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i $INTIF1 -o $INTIF2 -j ACCEPT
iptables -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE
echo "Associating internal address 192.0.0.2 with external address 128.0.0.2"
iptables -t nat -A PREROUTING -p tcp --dst 128.0.0.2 -j DNAT --to-destination 192.0.0.2
iptables -t nat -A PREROUTING -p udp --dst 128.0.0.2 -j DNAT --to-destination 192.0.0.2
iptables -t nat -A PREROUTING -p icmp --dst 128.0.0.2 -j DNAT --to-destination 192.0.0.2
iptables -t nat -A POSTROUTING -p tcp --dst 128.0.0.2 -j SNAT --to-source 192.0.0.2
iptables -t nat -A POSTROUTING -p udp --dst 128.0.0.2 -j SNAT --to-source 192.0.0.2
iptables -t nat -A POSTROUTING -p icmp --dst 128.0.0.2 -j SNAT --to-source 192.0.0.2
echo "Associating internal address 192.0.5.2 with external address 128.0.0.3"
iptables -t nat -A PREROUTING -p tcp --dst 128.0.0.3 -j DNAT --to-destination 192.0.5.2
iptables -t nat -A PREROUTING -p udp --dst 128.0.0.3 -j DNAT --to-destination 192.0.5.2
iptables -t nat -A PREROUTING -p icmp --dst 128.0.0.3 -j DNAT --to-destination 192.0.5.2
iptables -t nat -A POSTROUTING -p tcp --dst 128.0.0.3 -j SNAT --to-source 192.0.5.2
iptables -t nat -A POSTROUTING -p udp --dst 128.0.0.3 -j SNAT --to-source 192.0.5.2
iptables -t nat -A POSTROUTING -p icmp --dst 128.0.0.3 -j SNAT --to-source 192.0.5.2
# add logging
iptables -A INPUT -j LOG
#iptables -A FORWARD -j LOG
#iptables -t nat -A PREROUTING -j LOG
#iptables -t nat -A POSTROUTING -j LOG
#iptables -A OUTPUT -j LOG
#iptables -A block -j LOG
;;
'stop')
echo "Flushing iptables firewall..."
iptables -P INPUT ACCEPT
iptables -F INPUT
iptables -P OUTPUT ACCEPT
iptables -F OUTPUT
iptables -P FORWARD DROP
iptables -F FORWARD
#iptables -F block
iptables -t nat -F
;;
'restart')
$0 stop
$0 start
;;
*)
echo "$0 {start|stop}"
exit 1
;;
esac
exit 0