Mine

echo "Rule 0 (NAT)"
# 
$IPTABLES -t nat -A PREROUTING   -d 81.187.32.154 -j DNAT --to-destination 192.168.100.200 
echo "Rule 1 (NAT)"
# 
$IPTABLES -t nat -A POSTROUTING -o vlan1  -s 192.168.100.200 -j SNAT --to-source 81.187.32.154 
echo "Rule 2 (NAT)"
# 
$IPTABLES -t nat -A PREROUTING   -d 81.187.32.156 -j DNAT --to-destination 192.168.100.201 
echo "Rule 3 (NAT)"
# 
$IPTABLES -t nat -A POSTROUTING -o vlan1  -s 192.168.100.201 -j SNAT --to-source 81.187.32.156 
echo "Rule 4 (NAT)"
# 
$IPTABLES -t nat -A POSTROUTING -o vlan1  -s 192.168.100.0/24 -j SNAT --to-source 81.187.67.134 
echo "Rule 0 (lo)"
# 
$IPTABLES -A INPUT  -i lo  -m state --state NEW  -j ACCEPT 
$IPTABLES -A OUTPUT  -o lo  -m state --state NEW  -j ACCEPT