UDP nat question

Filipe Abrantes fla at inescporto.pt
Mon Apr 18 16:26:42 CEST 2005

Hi all,

I have a basic question about iptables UDP NAT.

Imagine that you have 2 UDP sessions in your private LAN using the same 
port. How does iptables nat these connections? One of the sessions will 
get one external port of the NAT machine and the other session will get 
another one? Does the usual MASQUERADE command suffice to achieve this?

iptables MASQUERADE command:


Hope I have made myself clear and,

Thanks for your attention

Filipe Abrantes

Filipe Lameiro Abrantes
Campus da FEUP
Rua Dr. Roberto Frias, 378
4200-465 Porto

Phone: +351 22 209 4266
E-mail: fla at inescporto.pt

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