[ILUG] iptables, nat and ftp stopped working

[John Allman]

Paul Jakma wrote:

>On Thu, 3 Oct 2002, John Allman wrote:
>
>  
>
>>In the end i got things going again by setting up passive ftp to work 
>>properly. i still dont know why active ftp didn't/doesn't work
>>    
>>
>
>because you only setup filtering rules. you need to add a rule in the 
>'nat' table, POSTROUTING to do SNAT/MASQUERADE, and make sure you have 
>the ftp connection tracking installed. :) OTOMH:
>
>iptables -t nat -I POSTROUTING -i <internal> -o <external> --dport ftp 
>-j MASQUERADE
>
>(or -j SNAT <myexternal ip>
>
>  
>
>>John
>>    
>>
>
>regards,
>  
>
sorry - i should have posted that bit of my iptables script too:

$ipt -t nat -A POSTROUTING -o $outif -j SNAT --to $outip

it does it for all traffic allowed out, not just ftp.

thanks

John