Iptables special config

["Vitor António das Neves Pinto" <vpinto@av.it.pt>]

Dear all,

I have a question regarding a special configuration with 
iptables, I hope you can help me:
-	Behind the NAT there’s a terminal with IP1 that sends a 
UDP packet to a host outside the NAT with IP2 (Source 
port=1033 Dport= 123)
-	The response to this packet (due to load balancing 
issues) comes from a machine outside the NAT with IP3 (not 
from IP2!!) with Source port=123 Dport=1033

Since iptables is configured as a port restricted NAT the 
response packet is dropped not reaching terminal with IP1… 
Any idea how to make the packet reach the terminal with 
IP1?
I know that with a full cone nat this wouldn’t happen…

Best regards,
Vitor Pinto