Re: Iptables SNAT for pkt generated by internal process

[Alexandru Dragoi <alexandru.dragoi@zoomnet.ro>]

moniacheli@tiscali.it wrote:

>I would like to use iptables to translate the source of IP datagrams 
>generated inside a router for some particular applications (such as 
>syslog: protocol UDP, destination port 514). I thought to use an 
>iptables rule defined by an OUTPUT chain (which let manipulate datagram 
>generated from local process) and by the target SNAT (which let to 
>translate ip source) -> iptables -t nat -A OUTPUT -p udp --dport 514 -j 
>SNAT --to x.x.x.x. The problem is that the OUTPUT chain cannot be used 
>with the target SNAT!
>Has anybody any idea about which is the best and simplest way to get 
>the result described above?
>
>Thanks for Your collaboration.
>Monia Cheli
>
>
>
>
>		
>Tiscali ADSL 4 Mega Flat 
>
>Naviga senza limiti a 19,95 Euro al mese con 4 Megabps di velocita'. Attiva subito: hai 2 MESI di canone adsl GRATIS!
>
>In piu', se sei raggiunto dalla rete Tiscali, telefoni senza pagare il canone Telecom. 
>
>Scopri subito come risparmiare! 
>
>http://abbonati.tiscali.it/prodotti/adsl/tc/4flat/
>	
>
>  
>
You do SNAT in POSTROUTING. Local generated packets also enter 
POSTROUTING. You may want to match source ip or .. you can mark packets 
in mangle OUTPUT, and then SNAT in POSTROUTING matching only the mark 
value with mark match.